diff --git a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/architect-mode-prompt.snap b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/architect-mode-prompt.snap
index ced0ede463..1dc60c72ed 100644
--- a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/architect-mode-prompt.snap
+++ b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/architect-mode-prompt.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/ask-mode-prompt.snap b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/ask-mode-prompt.snap
index 90bbc1ae34..b860218ffc 100644
--- a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/ask-mode-prompt.snap
+++ b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/ask-mode-prompt.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-disabled.snap b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-disabled.snap
index 9fdf29df77..553c5a5826 100644
--- a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-disabled.snap
+++ b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-disabled.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-enabled.snap b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-enabled.snap
index 3594c8054f..50220f79ca 100644
--- a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-enabled.snap
+++ b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/mcp-server-creation-enabled.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/partial-reads-enabled.snap b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/partial-reads-enabled.snap
index 00e7d3f5db..be78c1a121 100644
--- a/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/partial-reads-enabled.snap
+++ b/src/core/prompts/__tests__/__snapshots__/add-custom-instructions/partial-reads-enabled.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/consistent-system-prompt.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/consistent-system-prompt.snap
index ced0ede463..1dc60c72ed 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/consistent-system-prompt.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/consistent-system-prompt.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-computer-use-support.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-computer-use-support.snap
index 72e208ee6a..561360ca6e 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-computer-use-support.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-computer-use-support.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-false.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-false.snap
index ced0ede463..1dc60c72ed 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-false.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-false.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-true.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-true.snap
index 72aa071ce6..e1147f96bc 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-true.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-true.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-undefined.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-undefined.snap
index ced0ede463..1dc60c72ed 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-undefined.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-diff-enabled-undefined.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-different-viewport-size.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-different-viewport-size.snap
index 83271f47ad..fe856adb40 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-different-viewport-size.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-different-viewport-size.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-mcp-hub-provided.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-mcp-hub-provided.snap
index 3594c8054f..50220f79ca 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-mcp-hub-provided.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-mcp-hub-provided.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-undefined-mcp-hub.snap b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-undefined-mcp-hub.snap
index ced0ede463..1dc60c72ed 100644
--- a/src/core/prompts/__tests__/__snapshots__/system-prompt/with-undefined-mcp-hub.snap
+++ b/src/core/prompts/__tests__/__snapshots__/system-prompt/with-undefined-mcp-hub.snap
@@ -10,7 +10,7 @@ ALL responses MUST show ANY `language construct` OR filename reference as clicka
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting
 
diff --git a/src/core/prompts/sections/tool-use.ts b/src/core/prompts/sections/tool-use.ts
index c598fabae3..28d47d0985 100644
--- a/src/core/prompts/sections/tool-use.ts
+++ b/src/core/prompts/sections/tool-use.ts
@@ -3,7 +3,7 @@ export function getSharedToolUseSection(): string {
 
 TOOL USE
 
-You have access to a set of tools that are executed upon the user's approval. You can use one tool per message, and will receive the result of that tool use in the user's response. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
+You have access to a set of tools that are executed upon the user's approval. You must use exactly one tool per message, and every assistant message must include a tool call. You use tools step-by-step to accomplish a given task, with each tool use informed by the result of the previous tool use.
 
 # Tool Use Formatting