diff --git a/CHANGELOG.md b/CHANGELOG.md
index a17485683d..77b954397c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@
 ### Added
 - CI now runs a headless browser smoke test (`tests/browser_smoke.py`, `.github/workflows/browser-smoke.yml`) on every PR and push: it boots the real server agent-free and loads the key pages in Chromium, failing on any console error or uncaught JS exception. This catches the runtime-JS brick class (e.g. a `const` reassigned at runtime as in #3162, or a `function`/`window` name collision as in #2715/#2771) that `node --check`, ESLint, and the mocked test suite cannot see because they only manifest when a real browser executes the page. The smoke is credential-free — it strips `*_API_KEY` from the environment and drives no real model.
 
+### Changed
+
+- Activity disclosures now have a Settings → Appearance option to expand the activity feed by default, while still honoring per-turn manual collapse/expand choices.
+- Live Activity waiting rows now explain the agent's current step instead of stopping at `Waiting on model`, including a prompt/context review hint before tools run and the latest tool-derived action while the model chooses the next step.
+
 ## [v0.51.181] — 2026-05-30 — Release FA (stage-batchA — agent-cache eviction teardown + streaming finalize race)
 
 ### Fixed
diff --git a/api/config.py b/api/config.py
index 8fa873b63f..dd5cc13cd8 100644
--- a/api/config.py
+++ b/api/config.py
@@ -4822,6 +4822,7 @@ def _get_session_agent_lock(session_id: str) -> threading.Lock:
     "font_size": "default",  # small | default | large | xlarge
     "session_jump_buttons": False,  # show Start/End transcript jump pills
     "session_endless_scroll": False,  # auto-load older transcript pages while scrolling upward
+    "activity_feed_expanded_default": False,  # expand Activity disclosures by default for new turns
     "pinned_sessions_limit": 3,  # maximum active pinned sessions shown in the sidebar
     "inflight_state_max_sessions": 8,  # max active-stream recovery snapshots kept in browser localStorage
     "inflight_state_max_messages": 24,  # max recent messages kept per recovery snapshot
@@ -4985,6 +4986,7 @@ def load_settings() -> dict:
     "api_redact_enabled",
     "session_jump_buttons",
     "session_endless_scroll",
+    "activity_feed_expanded_default",
 }
 # Language codes are validated as short alphanumeric BCP-47-like tags (e.g. 'en', 'zh', 'fr')
 _SETTINGS_LANG_RE = __import__("re").compile(r"^[a-zA-Z]{2,10}(-[a-zA-Z0-9]{2,8})?$")
diff --git a/static/boot.js b/static/boot.js
index 9136a02856..15da1b79fc 100644
--- a/static/boot.js
+++ b/static/boot.js
@@ -1562,6 +1562,7 @@ function applyBotName(){
     window._whatsNewSummaryEnabled=!!s.whats_new_summary_enabled;
     window._showThinking=s.show_thinking!==false;
     window._simplifiedToolCalling=s.simplified_tool_calling!==false;
+    window._activityFeedExpandedDefault=!!s.activity_feed_expanded_default;
     window._sidebarDensity=(s.sidebar_density==='detailed'?'detailed':'compact');
     window._pinnedSessionsLimit=parseInt(s.pinned_sessions_limit||3,10)||3;
     window._inflightStateLimits={
diff --git a/static/i18n.js b/static/i18n.js
index 82a68a81ac..e6406c747d 100644
--- a/static/i18n.js
+++ b/static/i18n.js
@@ -531,6 +531,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: 'Load older messages while scrolling up',
 
     settings_desc_session_endless_scroll: 'When enabled, older messages load automatically as you scroll upward. When disabled, use the older-messages button.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Sidebar tabs',
     settings_desc_tab_visibility: 'Choose which tabs appear in the sidebar and rail. Chat and Settings are always visible.',
@@ -1842,6 +1844,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: 'Carica messaggi precedenti scorrendo in alto',
 
     settings_desc_session_endless_scroll: 'Se abilitato, i messaggi precedenti si caricano automaticamente scorrendo in alto. Se disabilitato, usa il pulsante messaggi precedenti.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Schede della barra laterale',
     settings_desc_tab_visibility: 'Scegli quali schede mostrare nella barra laterale e nel rail. Chat e Impostazioni sono sempre visibili.',
@@ -3145,6 +3149,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: '上スクロールで古いメッセージを読み込む',
 
     settings_desc_session_endless_scroll: '有効にすると、上にスクロールしたとき古いメッセージを自動で読み込みます。無効の場合は古いメッセージボタンを使います。',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'サイドバータブ',
     settings_desc_tab_visibility: 'サイドバーとレールに表示するタブを選択します。チャットと設定は常に表示されます。',
@@ -5018,6 +5024,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: 'Загружать старые сообщения при прокрутке вверх',
 
     settings_desc_session_endless_scroll: 'Если включено, старые сообщения загружаются автоматически при прокрутке вверх. Если выключено, используйте кнопку загрузки старых сообщений.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Вкладки боковой панели',
     settings_desc_tab_visibility: 'Выберите, какие вкладки отображаются на боковой панели и в рейле. Чат и настройки всегда видны.',
@@ -6247,6 +6255,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: 'Cargar mensajes antiguos al desplazarse hacia arriba',
 
     settings_desc_session_endless_scroll: 'Si está activado, los mensajes antiguos se cargan automáticamente al desplazarte hacia arriba. Si está desactivado, usa el botón de mensajes antiguos.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Pestañas de la barra lateral',
     settings_desc_tab_visibility: 'Elige qué pestañas aparecen en la barra lateral y el rail. Chat y Configuración siempre están visibles.',
@@ -7188,6 +7198,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: 'Ältere Nachrichten beim Hochscrollen laden',
 
     settings_desc_session_endless_scroll: 'Wenn aktiviert, werden ältere Nachrichten beim Hochscrollen automatisch geladen. Wenn deaktiviert, nutzt du den Button für ältere Nachrichten.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Seitenleiste-Tabs',
     settings_desc_tab_visibility: 'Wähle, welche Tabs in der Seitenleiste und im Rail angezeigt werden. Chat und Einstellungen sind immer sichtbar.',
@@ -8737,6 +8749,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: '向上滚动时加载更早的消息',
 
     settings_desc_session_endless_scroll: '启用后，向上滚动时会自动加载更早的消息。禁用时请使用加载更早消息按钮。',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: '侧边栏标签',
     settings_desc_tab_visibility: '选择在侧边栏和导航栏中显示哪些标签。聊天和设置始终可见。',
@@ -9231,6 +9245,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: '向上捲動時載入較早訊息',
 
     settings_desc_session_endless_scroll: '啟用後，向上捲動時會自動載入較早訊息。停用時請使用載入較早訊息按鈕。',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: '側邊欄標籤',
     settings_desc_tab_visibility: '選擇在側邊欄和導航列中顯示哪些標籤。聊天和設定始終可見。',
@@ -10610,6 +10626,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: 'Carregar mensagens antigas ao rolar para cima',
 
     settings_desc_session_endless_scroll: 'Quando ativado, mensagens antigas carregam automaticamente ao rolar para cima. Quando desativado, use o botão de mensagens antigas.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Abas da barra lateral',
     settings_desc_tab_visibility: 'Escolha quais abas aparecem na barra lateral e no rail. Chat e Configurações estão sempre visíveis.',
@@ -11816,6 +11834,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: '위로 스크롤할 때 이전 메시지 불러오기',
 
     settings_desc_session_endless_scroll: '활성화하면 위로 스크롤할 때 이전 메시지를 자동으로 불러옵니다. 비활성화하면 이전 메시지 버튼을 사용합니다.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: '사이드바 탭',
     settings_desc_tab_visibility: '사이드바와 레일에 표시할 탭을 선택하세요. 채팅과 설정은 항상 표시됩니다.',
@@ -13035,6 +13055,8 @@ const LOCALES = {
     settings_desc_session_jump_buttons: 'Affichez les boutons flottants de début et de fin lors de la lecture de longs historiques de session.',
     settings_label_session_endless_scroll: 'Charger les anciens messages en faisant défiler vers le haut',
     settings_desc_session_endless_scroll: 'Lorsqu\'ils sont activés, les anciens messages se chargent automatiquement lorsque vous faites défiler vers le haut. Lorsqu\'il est désactivé, utilisez le bouton des messages plus anciens.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Onglets de la barre latérale',
     settings_desc_tab_visibility: 'Choisissez quels onglets apparaissent dans la barre latérale et le rail. Chat et Paramètres sont toujours visibles.',
@@ -14357,6 +14379,8 @@ const LOCALES = {
     settings_label_session_endless_scroll: 'Yukarı kaydırırken eski mesajları yükle',
 
     settings_desc_session_endless_scroll: 'Etkinleştirildiğinde, yukarı doğru kaydırdığınızda eski mesajlar otomatik olarak yüklenir. Devre dışı bırakıldığında eski mesajlar düğmesini kullanın.',
+    settings_label_activity_feed_expanded_default: 'Expand activity feed by default',
+    settings_desc_activity_feed_expanded_default: 'Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.',
 
     settings_label_tab_visibility: 'Kenar çubuğu sekmeleri',
     settings_desc_tab_visibility: 'Kenar çubuğunda ve rayda hangi sekmelerin görüneceğini seçin. Sohbet ve Ayarlar her zaman görünür durumdadır.',
diff --git a/static/index.html b/static/index.html
index 5969bde249..7df69902ed 100644
--- a/static/index.html
+++ b/static/index.html
@@ -981,6 +981,13 @@ <h2 data-i18n="empty_title">What can I help with?</h2>
               </label>
               <div style="font-size:11px;color:var(--muted);margin-top:4px" data-i18n="settings_desc_session_endless_scroll">When enabled, older messages load automatically as you scroll upward. When disabled, use the older-messages button.</div>
             </div>
+            <div class="settings-field" style="margin-top:8px">
+              <label style="display:flex;align-items:center;gap:8px;cursor:pointer">
+                <input type="checkbox" id="settingsActivityFeedExpandedDefault" style="width:15px;height:15px;accent-color:var(--accent)">
+                <span data-i18n="settings_label_activity_feed_expanded_default">Expand activity feed by default</span>
+              </label>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px" data-i18n="settings_desc_activity_feed_expanded_default">Open new Activity disclosures automatically so tool and model progress is visible without an extra click. Per-turn manual collapse/expand choices still win.</div>
+            </div>
             <div class="settings-field">
               <label id="tabVisibilityLabel" data-i18n="settings_label_tab_visibility">Sidebar tabs</label>
               <div id="tabVisibilityChips" class="tab-visibility-chips" role="group" aria-labelledby="tabVisibilityLabel"></div>
diff --git a/static/panels.js b/static/panels.js
index fc8d4757fd..ef91a70825 100644
--- a/static/panels.js
+++ b/static/panels.js
@@ -5801,6 +5801,7 @@ function _appearancePayloadFromUi(){
     font_size: ($('settingsFontSize')||{}).value || localStorage.getItem('hermes-font-size') || 'default',
     session_jump_buttons: !!($('settingsSessionJumpButtons')||{}).checked,
     session_endless_scroll: !!($('settingsSessionEndlessScroll')||{}).checked,
+    activity_feed_expanded_default: !!($('settingsActivityFeedExpandedDefault')||{}).checked,
     hidden_tabs: _getHiddenTabs(),
   };
 }
@@ -5854,6 +5855,9 @@ async function _autosaveAppearanceSettings(payload){
       if(typeof _applySessionNavigationPrefs==='function') _applySessionNavigationPrefs();
     }
     window._sessionEndlessScrollEnabled=!!(saved&&saved.session_endless_scroll);
+    if(saved&&Object.prototype.hasOwnProperty.call(saved,'activity_feed_expanded_default')){
+      window._activityFeedExpandedDefault=!!saved.activity_feed_expanded_default;
+    }
     _setAppearanceAutosaveStatus('saved');
   }catch(e){
     console.warn('[settings] appearance autosave failed', e);
@@ -6068,6 +6072,15 @@ async function loadSettingsPanel(){
         _scheduleAppearanceAutosave();
       };
     }
+    const activityExpandedCb=$('settingsActivityFeedExpandedDefault');
+    if(activityExpandedCb){
+      activityExpandedCb.checked=!!settings.activity_feed_expanded_default;
+      window._activityFeedExpandedDefault=activityExpandedCb.checked;
+      activityExpandedCb.onchange=function(){
+        window._activityFeedExpandedDefault=this.checked;
+        _scheduleAppearanceAutosave();
+      };
+    }
     // Tab visibility chips (dynamically populated from DOM)
     var hiddenTabs=[];
     if(Array.isArray(settings.hidden_tabs)){
diff --git a/static/ui.js b/static/ui.js
index 4ca46c0f9b..9118fd49b4 100644
--- a/static/ui.js
+++ b/static/ui.js
@@ -5523,10 +5523,13 @@ function ensureActivityGroup(inner, opts){
   if(!group){
     group=document.createElement('div');
     let collapsed=opts.collapsed!==false;
+    if(window._activityFeedExpandedDefault===true) collapsed=false;
     const savedState=_readActivityDisclosureState(activityKey);
     // Restore the user's explicit expand intent when recreating the live
     // activity group within the same turn (#1298), then let persisted chat/turn
-    // state win across session switches and reloads.
+    // state win across session switches and reloads. Saved closed-state should
+    // override the default-expanded preference for settled groups the user has
+    // explicitly collapsed.
     if(live && _liveActivityUserExpanded === true) collapsed=false;
     else if(live && _liveActivityUserExpanded === false) collapsed=true;
     if(savedState==='open') collapsed=false;
@@ -7087,14 +7090,33 @@ function _activityProgressLabelForToolName(name){
   return 'Working';
 }
 
+function _activityLatestToolName(group){
+  if(!group) return '';
+  const running=group.querySelector('.tool-card.tool-card-running .tool-card-name');
+  const latest=running || Array.from(group.querySelectorAll('.tool-card-name')).pop();
+  return latest?String(latest.textContent||'').trim():'';
+}
+
+function _activityWaitingDetail(group,label=''){
+  const toolName=_activityLatestToolName(group);
+  if(toolName){
+    const action=_activityProgressLabelForToolName(toolName);
+    if(group&&group.querySelector('.tool-card.tool-card-running')) return `${action}: ${toolName}. Results will appear here.`;
+    return `Last step: ${action} (${toolName}); now choosing the next action or composing a response.`;
+  }
+  if(String(label||'').toLowerCase().includes('model')) return 'Reviewing the prompt and context, then choosing the next action or composing the response.';
+  return 'The agent is running; tool results and response text will appear here.';
+}
+
 function _activityLiveProgressLabel(group){
   if(!group||group.getAttribute('data-live-tool-call-group')!=='1') return '';
   const idleAge=_activityLastObservedAge(group);
   if(idleAge!==null&&idleAge>=90) return `No recent activity for ${_formatActiveElapsedTimer(idleAge)}`;
   const running=group.querySelector('.tool-card.tool-card-running .tool-card-name');
-  const latest=running || Array.from(group.querySelectorAll('.tool-card-name')).pop();
+  const latest=running?String(running.textContent||'').trim():_activityLatestToolName(group);
   const waiting=group.querySelector('.agent-activity-status-waiting .agent-activity-status-label');
-  if(latest) return _activityProgressLabelForToolName(latest.textContent);
+  if(latest) return _activityProgressLabelForToolName(latest);
+  if(waiting&&waiting.textContent&&String(waiting.textContent).toLowerCase().includes('model')) return 'Reviewing prompt and context';
   if(waiting&&waiting.textContent) return waiting.textContent;
   return 'Starting agent';
 }
@@ -7173,8 +7195,13 @@ function appendLiveToolCard(tc){
     status:toolDone?(tc.is_error?'error':'done'):'waiting',
     ts:_activityNowSeconds(),
   });
-  const waiting=body.querySelector('.agent-activity-status[data-activity-event-id="thinking-placeholder"] .agent-activity-status-label');
-  if(waiting&&!toolDone) waiting.textContent='Waiting on tool result';
+  const waiting=body.querySelector('.agent-activity-status[data-activity-event-id="thinking-placeholder"]');
+  if(waiting&&!toolDone){
+    const labelEl=waiting.querySelector('.agent-activity-status-label');
+    const detailEl=waiting.querySelector('.agent-activity-status-detail');
+    if(labelEl) labelEl.textContent='Waiting on tool result';
+    if(detailEl) detailEl.textContent=`${_activityProgressLabelForToolName(toolName)}: ${toolName}. Results will appear here.`;
+  }
   // Update existing card in place (tool_complete after tool_start)
   if(tid){
     const existing=body.querySelector(`.tool-card-row[data-live-tid="${CSS.escape(tid)}"]`);
@@ -7969,7 +7996,7 @@ function finalizeThinkingCard(){
     // when the user has not manually expanded this turn's activity group, or
     // has manually collapsed it. Otherwise the panel snaps shut whenever new
     // activity arrives, even mid-read.
-    if(_liveActivityUserExpanded !== true){
+    if(_liveActivityUserExpanded !== true && !(window._activityFeedExpandedDefault === true && _liveActivityUserExpanded !== false)){
       group.classList.add('tool-call-group-collapsed');
       const summary=group.querySelector('.tool-call-group-summary');
       if(summary) summary.setAttribute('aria-expanded','false');
@@ -8047,10 +8074,10 @@ function appendThinking(text='', options){
       detail='Creating the stream and sending your message…';
     }else if(hasRunningTool){
       label='Waiting on tool result';
-      detail='The tool is still running; the response will continue after it completes.';
+      detail=_activityWaitingDetail(group,label);
     }else if(hasToolCard){
       label='Waiting on model';
-      detail='Tool finished; waiting for the model to continue.';
+      detail=_activityWaitingDetail(group,label);
     }else{
       label='Waiting for first model token';
       detail='Stream connected; no model output has arrived yet.';
diff --git a/tests/test_live_activity_timeline.py b/tests/test_live_activity_timeline.py
index d1205ffa7f..26d337c813 100644
--- a/tests/test_live_activity_timeline.py
+++ b/tests/test_live_activity_timeline.py
@@ -29,9 +29,10 @@ def test_empty_thinking_placeholder_becomes_status_row_not_raw_thinking_card():
     assert "Waiting for first model token" in UI_JS
     assert "Stream connected; no model output has arrived yet." in UI_JS
     assert "Waiting on model" in UI_JS
-    assert "Tool finished; waiting for the model to continue." in UI_JS
+    assert "Reviewing the prompt and context, then choosing the next action or composing the response." in UI_JS
+    assert "Reviewing prompt and context" in UI_JS
     assert "Waiting on tool result" in UI_JS
-    assert "The tool is still running; the response will continue after it completes." in UI_JS
+    assert "Last step: ${action} (${toolName}); now choosing the next action or composing a response." in UI_JS
     assert "_thinkingActivityNode(thinkingText, false)" in UI_JS
 
 
@@ -45,6 +46,23 @@ def test_stream_start_refreshes_waiting_status_after_stream_id_arrives():
     assert refresh_idx < attach_idx
 
 
+def test_activity_feed_default_expand_setting_is_wired():
+    index_html = (REPO / "static" / "index.html").read_text(encoding="utf-8")
+    panels_js = (REPO / "static" / "panels.js").read_text(encoding="utf-8")
+    boot_js = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
+    config_py = (REPO / "api" / "config.py").read_text(encoding="utf-8")
+
+    assert 'id="settingsActivityFeedExpandedDefault"' in index_html
+    assert "settings_label_activity_feed_expanded_default" in index_html
+    assert '"activity_feed_expanded_default": False' in config_py
+    assert "activity_feed_expanded_default" in panels_js
+    assert "window._activityFeedExpandedDefault=!!s.activity_feed_expanded_default;" in boot_js
+    assert "if(window._activityFeedExpandedDefault===true) collapsed=false;" in UI_JS
+    finalize_fn = UI_JS.split("function finalizeThinkingCard")[1].split("\nfunction ")[0]
+    assert "_activityFeedExpandedDefault" in finalize_fn
+    assert "_liveActivityUserExpanded !== false" in finalize_fn
+
+
 def test_tool_events_update_activity_timeline_and_summary():
     assert "Tool finished: ${toolName}" in UI_JS
     assert "Running tool: ${toolName}" in UI_JS