diff --git a/CLI/cmux.swift b/CLI/cmux.swift
index b257328d25c8..fd22dd063559 100644
--- a/CLI/cmux.swift
+++ b/CLI/cmux.swift
@@ -5325,7 +5325,7 @@ struct CMUXCLI {
                 return
             }
         }
-        if command == "setup-hooks" || command == "uninstall-hooks" { try runSetupHooks(uninstall: command == "uninstall-hooks"); return } // Backwards compatibility for old hook setup docs/scripts.
+        if command == "setup-hooks" || command == "uninstall-hooks" { try runSetupHooks(uninstall: command == "uninstall-hooks", arguments: try Self.parseHooksSetupArguments(commandArgs)); return } // Backwards compatibility for old hook setup docs/scripts.
         if (command == "codex-hook" || command == "feed-hook"), processEnv["CMUX_SURFACE_ID"]?.isEmpty != false, processEnv["CMUX_WORKSPACE_ID"]?.isEmpty != false,
            !commandArgs.contains(where: { $0 == "--workspace" || $0 == "--surface" || $0.hasPrefix("--workspace=") || $0.hasPrefix("--surface=") }) { print("{}"); return } // Backwards compatibility for old installed hooks outside cmux terminals.
         if command == "hooks" {
@@ -42243,14 +42243,14 @@ export default {
         case "setup":
             try runSetupHooks(
                 uninstall: false,
-                positionalAgentFilter: try Self.hooksSetupPositionalAgentFilter(from: Array(commandArgs.dropFirst()))
+                arguments: try Self.parseHooksSetupArguments(Array(commandArgs.dropFirst()))
             )
             return true
 
         case "uninstall":
             try runSetupHooks(
                 uninstall: true,
-                positionalAgentFilter: try Self.hooksSetupPositionalAgentFilter(from: Array(commandArgs.dropFirst()))
+                arguments: try Self.parseHooksSetupArguments(Array(commandArgs.dropFirst()))
             )
             return true
 
@@ -42430,34 +42430,71 @@ export default {
         }
     }
 
-    private static func hooksSetupPositionalAgentFilter(from args: [String]) throws -> String? {
-        var skipNext = false
+    /// The target and mode `cmux hooks setup`/`uninstall` (and the legacy
+    /// `setup-hooks`/`uninstall-hooks`) were asked for.
+    private struct HooksSetupArguments {
+        var flagAgent: String?
         var positionalAgent: String?
-        for arg in args {
-            if skipNext {
-                skipNext = false
-                continue
+        var uninstall = false
+    }
+
+    /// Parses setup/uninstall arguments, rejecting anything it doesn't know
+    /// so a typo can't fall back to every agent.
+    private static func parseHooksSetupArguments(_ args: [String]) throws -> HooksSetupArguments {
+        var parsed = HooksSetupArguments()
+        func setFlagAgent(_ value: String) throws {
+            guard !value.isEmpty, !value.hasPrefix("-") else {
+                throw CLIError(message: String(
+                    localized: "cli.hooks.setup.error.agentRequiresValue",
+                    defaultValue: "--agent requires a value. Usage: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+                ))
+            }
+            if let existing = parsed.flagAgent, existing != value {
+                throw CLIError(message: String(
+                    localized: "cli.hooks.setup.error.conflictingAgent",
+                    defaultValue: "--agent was given more than once with different values. Specify one agent."
+                ))
             }
+            parsed.flagAgent = value
+        }
+        var index = 0
+        while index < args.count {
+            let arg = args[index]
+            index += 1
             switch arg {
             case "--agent":
-                skipNext = true
-            case "--yes", "-y", "--uninstall":
+                try setFlagAgent(index < args.count ? args[index] : "")
+                index += 1
+            case "--yes", "-y":
                 continue
+            case "--uninstall":
+                parsed.uninstall = true
             default:
-                if !arg.hasPrefix("-") {
-                    if positionalAgent != nil {
+                if arg.hasPrefix("--agent=") {
+                    try setFlagAgent(String(arg.dropFirst("--agent=".count)))
+                } else if arg.hasPrefix("-") {
+                    let name = arg.split(separator: "=", maxSplits: 1).first.map(String.init) ?? arg
+                    throw CLIError(message: String.localizedStringWithFormat(
+                        String(
+                            localized: "cli.hooks.setup.error.unknownOption",
+                            defaultValue: "Unknown option %@. Usage: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+                        ),
+                        name
+                    ))
+                } else {
+                    if parsed.positionalAgent != nil {
                         throw CLIError(message: "Too many hooks targets: specify at most one positional agent")
                     }
-                    positionalAgent = arg
+                    parsed.positionalAgent = arg
                 }
             }
         }
-        return positionalAgent
+        return parsed
     }
 
-    private func runSetupHooks(uninstall: Bool = false, positionalAgentFilter: String? = nil) throws {
-        let args = ProcessInfo.processInfo.arguments
-        let flagAgentFilter = optionValue(args, name: "--agent")
+    private func runSetupHooks(uninstall: Bool = false, arguments: HooksSetupArguments) throws {
+        let flagAgentFilter = arguments.flagAgent
+        let positionalAgentFilter = arguments.positionalAgent
         if let flagAgentFilter, let positionalAgentFilter {
             guard let flagDef = Self.agentDef(named: flagAgentFilter) else {
                 throw CLIError(message: "Unknown hooks target: \(flagAgentFilter)")
@@ -42479,7 +42516,7 @@ export default {
         } else {
             agentFilterDef = nil
         }
-        let isUninstall = uninstall || args.contains("--uninstall")
+        let isUninstall = uninstall || arguments.uninstall
         let fm = FileManager.default
         let verb = isUninstall ? "uninstalling" : "installing"
         print("cmux hooks \(isUninstall ? "uninstall" : "setup"): \(verb) agent hooks")
diff --git a/Resources/Localizable.xcstrings b/Resources/Localizable.xcstrings
index f5fb9110718c..c7113553a28a 100644
--- a/Resources/Localizable.xcstrings
+++ b/Resources/Localizable.xcstrings
@@ -235781,7 +235781,7 @@
         }
       }
     },
-  "machines.new.plan.loading": {
+    "machines.new.plan.loading": {
     "extractionState": "manual",
     "localizations": {
       "en": {
@@ -235906,7 +235906,7 @@
       }
     }
   },
-  "machines.new.plan.retry": {
+    "machines.new.plan.retry": {
     "extractionState": "manual",
     "localizations": {
       "en": {
@@ -236031,7 +236031,7 @@
       }
     }
   },
-  "machines.new.plan.error": {
+    "machines.new.plan.error": {
     "extractionState": "manual",
     "localizations": {
       "en": {
@@ -358728,131 +358728,6 @@
         }
       }
     },
-    "settings.search.alias.setting.terminal.copy-confirmation": {
-      "extractionState": "manual",
-      "localizations": {
-        "ar": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse تأكيد نسخ حافظة تحديد"
-          }
-        },
-        "bs": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse potvrda kopirano međuspremnik odabir"
-          }
-        },
-        "da": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse bekræftelse kopieret udklipsholder markering"
-          }
-        },
-        "de": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse Bestätigung kopiert Zwischenablage Auswahl"
-          }
-        },
-        "en": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse"
-          }
-        },
-        "es": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse confirmación copiado portapapeles selección"
-          }
-        },
-        "fr": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse confirmation copié presse-papiers sélection"
-          }
-        },
-        "it": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse conferma copiato appunti selezione"
-          }
-        },
-        "ja": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 確認 コピー クリップボード 選択"
-          }
-        },
-        "km": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse បញ្ជាក់ ចម្លង ក្ដារតម្រៀប ជ្រើស"
-          }
-        },
-        "ko": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 확인 복사됨 클립보드 선택"
-          }
-        },
-        "nb": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse bekreftelse kopiert utklippstavle markering"
-          }
-        },
-        "pl": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse potwierdzenie skopiowano schowek zaznaczenie"
-          }
-        },
-        "pt-BR": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse confirmação copiado área de transferência seleção"
-          }
-        },
-        "ru": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse подтверждение скопировано буфер обмена выделение"
-          }
-        },
-        "th": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse ยืนยัน คัดลอก คลิปบอร์ด เลือก"
-          }
-        },
-        "tr": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse onay kopyalandı pano seçim"
-          }
-        },
-        "uk": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse підтвердження скопійовано буфер обміну виділення"
-          }
-        },
-        "zh-Hans": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 确认 已复制 剪贴板 选择"
-          }
-        },
-        "zh-Hant": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 確認 已複製 剪貼簿 選取"
-          }
-        }
-      }
-    },
     "settings.search.alias.setting.terminal.reflow-hard-wrap-on-copy": {
       "extractionState": "manual",
       "localizations": {
@@ -366360,256 +366235,6 @@
         }
       }
     },
-    "settings.terminal.showCopyConfirmation": {
-      "extractionState": "manual",
-      "localizations": {
-        "ar": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "إظهار تأكيد النسخ"
-          }
-        },
-        "bs": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Prikaži potvrdu kopiranja"
-          }
-        },
-        "da": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Vis kopieringsbekræftelse"
-          }
-        },
-        "de": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Kopierbestätigung anzeigen"
-          }
-        },
-        "en": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Show Copy Confirmation"
-          }
-        },
-        "es": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Mostrar confirmación de copia"
-          }
-        },
-        "fr": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Afficher la confirmation de copie"
-          }
-        },
-        "it": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Mostra conferma di copia"
-          }
-        },
-        "ja": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "コピーの確認を表示"
-          }
-        },
-        "km": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "បង្ហាញការបញ្ជាក់ការចម្លង"
-          }
-        },
-        "ko": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "복사 확인 표시"
-          }
-        },
-        "nb": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Vis kopieringsbekreftelse"
-          }
-        },
-        "pl": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Pokazuj potwierdzenie kopiowania"
-          }
-        },
-        "pt-BR": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Mostrar confirmação de cópia"
-          }
-        },
-        "ru": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Показывать подтверждение копирования"
-          }
-        },
-        "th": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "แสดงการยืนยันการคัดลอก"
-          }
-        },
-        "tr": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Kopyalama onayını göster"
-          }
-        },
-        "uk": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Показувати підтвердження копіювання"
-          }
-        },
-        "zh-Hans": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "显示复制确认"
-          }
-        },
-        "zh-Hant": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "顯示複製確認"
-          }
-        }
-      }
-    },
-    "settings.terminal.showCopyConfirmation.subtitle": {
-      "extractionState": "manual",
-      "localizations": {
-        "ar": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "يعرض «تم النسخ إلى الحافظة» لفترة وجيزة أسفل الطرفية عندما يؤدي تحديد النص إلى نسخه."
-          }
-        },
-        "bs": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Kratko prikazuje „Kopirano u međuspremnik“ na dnu terminala kada se odabrani tekst kopira."
-          }
-        },
-        "da": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Viser kortvarigt „Kopieret til udklipsholder“ nederst i en terminal, når markering af tekst kopierer den."
-          }
-        },
-        "de": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Zeigt unten im Terminal kurz „In die Zwischenablage kopiert“ an, wenn durch Auswählen von Text kopiert wird."
-          }
-        },
-        "en": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Briefly shows “Copied to clipboard” at the bottom of a terminal when selecting text copies it."
-          }
-        },
-        "es": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Muestra brevemente «Copiado al portapapeles» en la parte inferior de una terminal cuando al seleccionar texto se copia."
-          }
-        },
-        "fr": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Affiche brièvement « Copié dans le presse-papiers » en bas d’un terminal lorsque la sélection de texte le copie."
-          }
-        },
-        "it": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Mostra brevemente «Copiato negli appunti» in fondo a un terminale quando la selezione del testo lo copia."
-          }
-        },
-        "ja": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "テキストを選択してコピーしたときに、ターミナルの下部に「クリップボードにコピーしました」を短く表示します。"
-          }
-        },
-        "km": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "បង្ហាញ «បានចម្លងទៅក្ដារតម្រៀប» មួយភ្លែតនៅខាងក្រោម terminal នៅពេលការជ្រើសអត្ថបទចម្លងវា។"
-          }
-        },
-        "ko": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "텍스트를 선택해 복사하면 터미널 하단에 “클립보드에 복사됨”을 잠시 표시합니다."
-          }
-        },
-        "nb": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Viser kort «Kopiert til utklippstavlen» nederst i en terminal når markering av tekst kopierer den."
-          }
-        },
-        "pl": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Na chwilę wyświetla „Skopiowano do schowka” u dołu terminala, gdy zaznaczenie tekstu go kopiuje."
-          }
-        },
-        "pt-BR": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Mostra brevemente “Copiado para a área de transferência” na parte inferior do terminal quando selecionar texto o copia."
-          }
-        },
-        "ru": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Ненадолго показывает «Скопировано в буфер обмена» внизу терминала, когда выделение текста копирует его."
-          }
-        },
-        "th": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "แสดง “คัดลอกไปยังคลิปบอร์ดแล้ว” ชั่วครู่ที่ด้านล่างของเทอร์มินัลเมื่อการเลือกข้อความคัดลอกข้อความนั้น"
-          }
-        },
-        "tr": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Metin seçimi onu kopyaladığında terminalin altında kısa süreliğine “Panoya kopyalandı” gösterir."
-          }
-        },
-        "uk": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "Ненадовго показує «Скопійовано в буфер обміну» внизу термінала, коли виділення тексту копіює його."
-          }
-        },
-        "zh-Hans": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "选择文本并复制时，在终端底部短暂显示“已复制到剪贴板”。"
-          }
-        },
-        "zh-Hant": {
-          "stringUnit": {
-            "state": "translated",
-            "value": "選取文字並複製時，在終端機底部短暫顯示「已複製到剪貼簿」。"
-          }
-        }
-      }
-    },
     "settings.terminal.reflowHardWrapOnCopy": {
       "extractionState": "manual",
       "localizations": {
@@ -619288,6 +618913,558 @@
         }
       }
     },
+    "cli.hooks.setup.error.agentRequiresValue": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent requires a value. Usage: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "ar": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "يتطلب --agent قيمة. الاستخدام: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "de": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent erfordert einen Wert. Verwendung: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "es": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent requiere un valor. Uso: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "fr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent nécessite une valeur. Utilisation : cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent には値が必要です。使い方: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent에는 값이 필요합니다. 사용법: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent 需要一个值。用法：cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent 需要一個值。用法：cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        }
+      }
+    },
+    "cli.hooks.setup.error.unknownOption": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Unknown option %@. Usage: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "ar": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "خيار غير معروف %@. الاستخدام: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "de": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Unbekannte Option %@. Verwendung: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "es": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Opción desconocida %@. Uso: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "fr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Option inconnue %@. Utilisation : cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "不明なオプション %@。使い方: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "알 수 없는 옵션 %@. 사용법: cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "未知选项 %@。用法：cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "未知的選項 %@。用法：cmux hooks setup [agent] [--agent <name>] [--yes|-y]"
+          }
+        }
+      }
+    },
+    "cli.hooks.setup.error.conflictingAgent": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent was given more than once with different values. Specify one agent."
+          }
+        },
+        "ar": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "تم تمرير --agent أكثر من مرة بقيم مختلفة. حدد وكيلًا واحدًا."
+          }
+        },
+        "de": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent wurde mehrmals mit unterschiedlichen Werten angegeben. Gib einen Agenten an."
+          }
+        },
+        "es": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent se indicó más de una vez con valores distintos. Indica un solo agente."
+          }
+        },
+        "fr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent a été indiqué plusieurs fois avec des valeurs différentes. Indiquez un seul agent."
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent が異なる値で複数回指定されました。エージェントを 1 つだけ指定してください。"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent가 서로 다른 값으로 여러 번 지정되었습니다. 에이전트를 하나만 지정하세요."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent 被多次指定且值不同。请只指定一个代理。"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "--agent 被多次指定且值不同。請只指定一個代理程式。"
+          }
+        }
+      }
+    },
+    "settings.search.alias.setting.terminal.copy-confirmation": {
+      "extractionState": "manual",
+      "localizations": {
+        "ar": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse تأكيد نسخ حافظة تحديد"
+          }
+        },
+        "bs": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse potvrda kopirano međuspremnik odabir"
+          }
+        },
+        "da": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse bekræftelse kopieret udklipsholder markering"
+          }
+        },
+        "de": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse Bestätigung kopiert Zwischenablage Auswahl"
+          }
+        },
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse"
+          }
+        },
+        "es": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse confirmación copiado portapapeles selección"
+          }
+        },
+        "fr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse confirmation copié presse-papiers sélection"
+          }
+        },
+        "it": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse conferma copiato appunti selezione"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 確認 コピー クリップボード 選択"
+          }
+        },
+        "km": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse បញ្ជាក់ ចម្លង ក្ដារតម្រៀប ជ្រើស"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 확인 복사됨 클립보드 선택"
+          }
+        },
+        "nb": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse bekreftelse kopiert utklippstavle markering"
+          }
+        },
+        "pl": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse potwierdzenie skopiowano schowek zaznaczenie"
+          }
+        },
+        "pt-BR": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse confirmação copiado área de transferência seleção"
+          }
+        },
+        "ru": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse подтверждение скопировано буфер обмена выделение"
+          }
+        },
+        "th": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse ยืนยัน คัดลอก คลิปบอร์ด เลือก"
+          }
+        },
+        "tr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse onay kopyalandı pano seçim"
+          }
+        },
+        "uk": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse підтвердження скопійовано буфер обміну виділення"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 确认 已复制 剪贴板 选择"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "terminal.showCopyConfirmation copy confirmation copied clipboard feedback indicator toast popup copy on selection select mouse 確認 已複製 剪貼簿 選取"
+          }
+        }
+      }
+    },
+    "settings.terminal.showCopyConfirmation": {
+      "extractionState": "manual",
+      "localizations": {
+        "ar": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "إظهار تأكيد النسخ"
+          }
+        },
+        "bs": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Prikaži potvrdu kopiranja"
+          }
+        },
+        "da": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Vis kopieringsbekræftelse"
+          }
+        },
+        "de": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Kopierbestätigung anzeigen"
+          }
+        },
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Show Copy Confirmation"
+          }
+        },
+        "es": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Mostrar confirmación de copia"
+          }
+        },
+        "fr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Afficher la confirmation de copie"
+          }
+        },
+        "it": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Mostra conferma di copia"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "コピーの確認を表示"
+          }
+        },
+        "km": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "បង្ហាញការបញ្ជាក់ការចម្លង"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "복사 확인 표시"
+          }
+        },
+        "nb": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Vis kopieringsbekreftelse"
+          }
+        },
+        "pl": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Pokazuj potwierdzenie kopiowania"
+          }
+        },
+        "pt-BR": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Mostrar confirmação de cópia"
+          }
+        },
+        "ru": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Показывать подтверждение копирования"
+          }
+        },
+        "th": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "แสดงการยืนยันการคัดลอก"
+          }
+        },
+        "tr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Kopyalama onayını göster"
+          }
+        },
+        "uk": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Показувати підтвердження копіювання"
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "显示复制确认"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "顯示複製確認"
+          }
+        }
+      }
+    },
+    "settings.terminal.showCopyConfirmation.subtitle": {
+      "extractionState": "manual",
+      "localizations": {
+        "ar": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "يعرض «تم النسخ إلى الحافظة» لفترة وجيزة أسفل الطرفية عندما يؤدي تحديد النص إلى نسخه."
+          }
+        },
+        "bs": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Kratko prikazuje „Kopirano u međuspremnik“ na dnu terminala kada se odabrani tekst kopira."
+          }
+        },
+        "da": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Viser kortvarigt „Kopieret til udklipsholder“ nederst i en terminal, når markering af tekst kopierer den."
+          }
+        },
+        "de": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Zeigt unten im Terminal kurz „In die Zwischenablage kopiert“ an, wenn durch Auswählen von Text kopiert wird."
+          }
+        },
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Briefly shows “Copied to clipboard” at the bottom of a terminal when selecting text copies it."
+          }
+        },
+        "es": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Muestra brevemente «Copiado al portapapeles» en la parte inferior de una terminal cuando al seleccionar texto se copia."
+          }
+        },
+        "fr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Affiche brièvement « Copié dans le presse-papiers » en bas d’un terminal lorsque la sélection de texte le copie."
+          }
+        },
+        "it": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Mostra brevemente «Copiato negli appunti» in fondo a un terminale quando la selezione del testo lo copia."
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "テキストを選択してコピーしたときに、ターミナルの下部に「クリップボードにコピーしました」を短く表示します。"
+          }
+        },
+        "km": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "បង្ហាញ «បានចម្លងទៅក្ដារតម្រៀប» មួយភ្លែតនៅខាងក្រោម terminal នៅពេលការជ្រើសអត្ថបទចម្លងវា។"
+          }
+        },
+        "ko": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "텍스트를 선택해 복사하면 터미널 하단에 “클립보드에 복사됨”을 잠시 표시합니다."
+          }
+        },
+        "nb": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Viser kort «Kopiert til utklippstavlen» nederst i en terminal når markering av tekst kopierer den."
+          }
+        },
+        "pl": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Na chwilę wyświetla „Skopiowano do schowka” u dołu terminala, gdy zaznaczenie tekstu go kopiuje."
+          }
+        },
+        "pt-BR": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Mostra brevemente “Copiado para a área de transferência” na parte inferior do terminal quando selecionar texto o copia."
+          }
+        },
+        "ru": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Ненадолго показывает «Скопировано в буфер обмена» внизу терминала, когда выделение текста копирует его."
+          }
+        },
+        "th": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "แสดง “คัดลอกไปยังคลิปบอร์ดแล้ว” ชั่วครู่ที่ด้านล่างของเทอร์มินัลเมื่อการเลือกข้อความคัดลอกข้อความนั้น"
+          }
+        },
+        "tr": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Metin seçimi onu kopyaladığında terminalin altında kısa süreliğine “Panoya kopyalandı” gösterir."
+          }
+        },
+        "uk": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Ненадовго показує «Скопійовано в буфер обміну» внизу термінала, коли виділення тексту копіює його."
+          }
+        },
+        "zh-Hans": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "选择文本并复制时，在终端底部短暂显示“已复制到剪贴板”。"
+          }
+        },
+        "zh-Hant": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "選取文字並複製時，在終端機底部短暫顯示「已複製到剪貼簿」。"
+          }
+        }
+      }
+    },
     "terminal.copyConfirmation.title": {
       "extractionState": "manual",
       "localizations": {
diff --git a/tests/test-execution.toml b/tests/test-execution.toml
index 0bf8ed273b1d..3c774c27719f 100644
--- a/tests/test-execution.toml
+++ b/tests/test-execution.toml
@@ -1491,6 +1491,11 @@ path = "tests/test_claude_hook_spool.py"
 lane = "macos-cli-product"
 requirements = ["cmux-cli"]
 
+[[test]]
+path = "tests/test_cli_hooks_setup_arguments.py"
+lane = "macos-cli-product"
+requirements = ["cmux-cli"]
+
 [[test]]
 path = "tests/test_ci_machine_failure.py"
 lane = "linux-guard"
diff --git a/tests/test_ci_test_execution_registry.py b/tests/test_ci_test_execution_registry.py
index d5f6f7028e27..2465270c49aa 100644
--- a/tests/test_ci_test_execution_registry.py
+++ b/tests/test_ci_test_execution_registry.py
@@ -63,8 +63,14 @@ def test_cli_product_lane_selects_the_hook_spool_regression(self) -> None:
              "--lane", "macos-cli-product", "--list"],
             cwd=ROOT, capture_output=True, text=True, check=True,
         )
-        self.assertEqual(result.stdout.splitlines(), ["tests/test_claude_hook_spool.py"])
-        errors, _, _ = validator.validate(ROOT, added={"tests/test_claude_hook_spool.py"})
+        self.assertEqual(
+            result.stdout.splitlines(),
+            ["tests/test_claude_hook_spool.py", "tests/test_cli_hooks_setup_arguments.py"],
+        )
+        errors, _, _ = validator.validate(
+            ROOT,
+            added={"tests/test_claude_hook_spool.py", "tests/test_cli_hooks_setup_arguments.py"},
+        )
         self.assertEqual(errors, [])
 
     def make_root(self, *, tests: list[str], registry: str) -> Path:
diff --git a/tests/test_cli_hooks_setup_arguments.py b/tests/test_cli_hooks_setup_arguments.py
new file mode 100644
index 000000000000..03aaa5b658aa
--- /dev/null
+++ b/tests/test_cli_hooks_setup_arguments.py
@@ -0,0 +1,109 @@
+#!/usr/bin/env python3
+"""`cmux hooks setup` and `uninstall` reject options they don't understand.
+
+An unknown or valueless option used to be skipped, so the command fell back
+to every agent and rewrote their configs. Each case runs the real CLI against
+a temporary home with no agent binaries on PATH. Pi hooks install without a
+binary, so an unfiltered setup always writes Pi's extension there; a rejected
+command must exit non-zero and write nothing.
+"""
+import os
+from pathlib import Path
+import subprocess
+import tempfile
+import unittest
+
+from claude_teams_test_utils import resolve_cmux_cli
+
+
+class HooksSetupArgumentTests(unittest.TestCase):
+    def setUp(self):
+        self.temp = tempfile.TemporaryDirectory(prefix='cmux-hooks-args-')
+        self.addCleanup(self.temp.cleanup)
+        self.home = Path(self.temp.name) / 'home'
+        self.home.mkdir()
+        self.cli = str(resolve_cmux_cli())
+
+    def run_cli(self, *args):
+        # A minimal environment so no agent config override points outside
+        # the temporary home.
+        env = {
+            'HOME': str(self.home),
+            'CFFIXED_USER_HOME': str(self.home),
+            'PATH': '/usr/bin:/bin:/usr/sbin:/sbin',
+            'TMPDIR': os.environ.get('TMPDIR', '/tmp'),
+            'CMUX_CLI_SENTRY_DISABLED': '1',
+            'CMUX_SOCKET_PATH': str(Path(self.temp.name) / 'no-socket.sock'),
+        }
+        # No stdin, so a confirmation prompt can't wait on the test runner.
+        return subprocess.run([self.cli, *args], env=env, stdin=subprocess.DEVNULL,
+                              capture_output=True, text=True, timeout=30, check=False)
+
+    def written_files(self):
+        return sorted(str(p.relative_to(self.home)) for p in self.home.rglob('*') if p.is_file())
+
+    def assert_rejected(self, args, message):
+        result = self.run_cli(*args)
+        output = result.stdout + result.stderr
+        self.assertNotEqual(result.returncode, 0, f'{args} should fail:\n{output}')
+        self.assertIn(message, output, f'{args}:\n{output}')
+        self.assertEqual(self.written_files(), [], f'{args} wrote files:\n{output}')
+
+    def test_unknown_option_is_rejected_before_writing(self):
+        for subcommand in ('setup', 'uninstall'):
+            for args in (['--agnt', 'codex'], ['--yes', '--agnt=codex']):
+                with self.subTest(subcommand=subcommand, args=args):
+                    self.assert_rejected(['hooks', subcommand, *args], 'Unknown option --agnt')
+
+    def test_agent_option_requires_a_value(self):
+        for args in (['hooks', 'setup', '--agent'],
+                     ['hooks', 'setup', '--agent', '--yes'],
+                     ['hooks', 'setup', '--agent='],
+                     ['hooks', 'uninstall', '--agent']):
+            with self.subTest(args=args):
+                self.assert_rejected(args, '--agent requires a value')
+
+    def test_repeated_agent_with_different_values_is_rejected(self):
+        self.assert_rejected(['hooks', 'setup', '--agent', 'codex', '--agent', 'pi'],
+                             '--agent was given more than once with different values')
+
+    def test_positional_and_agent_option_must_agree(self):
+        self.assert_rejected(['hooks', 'setup', 'codex', '--agent', 'pi'], 'Conflicting hooks target')
+
+    def test_legacy_aliases_reject_unknown_options(self):
+        for command in ('setup-hooks', 'uninstall-hooks'):
+            with self.subTest(command=command):
+                self.assert_rejected([command, '--agnt', 'codex'], 'Unknown option --agnt')
+
+    def test_help_prints_usage_without_writing(self):
+        for args in (['hooks', 'setup', '--help'], ['hooks', 'uninstall', '-h']):
+            with self.subTest(args=args):
+                result = self.run_cli(*args)
+                self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
+                self.assertIn('Usage: cmux hooks setup', result.stdout)
+                self.assertEqual(self.written_files(), [])
+
+    def test_documented_forms_still_work(self):
+        for args in (['hooks', 'setup', 'pi', '--yes'],
+                     ['hooks', 'setup', '--agent', 'pi', '-y'],
+                     ['hooks', 'setup', '--agent=pi'],
+                     ['hooks', 'setup', 'pi', '--agent', 'pi'],
+                     ['hooks', 'setup', '--uninstall', 'pi']):
+            with self.subTest(args=args):
+                result = self.run_cli(*args)
+                self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
+                self.assertIn('pi', result.stdout)
+
+
+    def test_agent_name_aliases_still_resolve(self):
+        for args, agent in ((['hooks', 'setup', 'agy', '--yes'], 'antigravity'),
+                            (['hooks', 'setup', '--agent', 'rovo', '--yes'], 'rovodev'),
+                            (['hooks', 'uninstall', '--agent=agy', '--yes'], 'antigravity')):
+            with self.subTest(args=args):
+                result = self.run_cli(*args)
+                self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
+                self.assertIn(f'  {agent}:', result.stdout)
+
+
+if __name__ == '__main__':
+    unittest.main()