diff --git a/src/renderer/src/lib/agent-launch-tab-publication.ts b/src/renderer/src/lib/agent-launch-tab-publication.ts
index 20116563991..4c9959ea2d1 100644
--- a/src/renderer/src/lib/agent-launch-tab-publication.ts
+++ b/src/renderer/src/lib/agent-launch-tab-publication.ts
@@ -103,11 +103,6 @@ export function publishAgentLaunchTab(
   if (request.prompt) {
     rememberAgentLaunchPanePrompt(tabId, request.prompt)
   }
-  if (tab.id !== tabId) {
-    // createTab mints a fresh id on a collision it saw and we did not; that tab would never attach.
-    useAppStore.getState().closeTab(tab.id, { recordInteraction: false })
-    throw new Error('agent_launch_tab_id_taken')
-  }
   if (placement.anchorTabId) {
     const unifiedTabId = useAppStore
       .getState()
diff --git a/src/renderer/src/store/slices/store-create-tab-id-hint.test.ts b/src/renderer/src/store/slices/store-create-tab-id-hint.test.ts
index 6dbda55207c..643b9454e97 100644
--- a/src/renderer/src/store/slices/store-create-tab-id-hint.test.ts
+++ b/src/renderer/src/store/slices/store-create-tab-id-hint.test.ts
@@ -47,7 +47,7 @@ describe('createTab tabId hint', () => {
     expect(tab.id).toBe(hintedId)
   })
 
-  it('falls back to a fresh id on collision and warns', () => {
+  it('rejects a taken id instead of minting a fresh one', () => {
     const store = createTestStore()
     const wt = 'repo1::/path/wt-collision'
     const existingId = 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee'
@@ -63,14 +63,12 @@ describe('createTab tabId hint', () => {
       unifiedTabsByWorktree: {}
     })
 
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
-    try {
-      const tab = store.getState().createTab(wt, undefined, undefined, { id: existingId })
-      expect(tab.id).not.toBe(existingId)
-      expect(warn).toHaveBeenCalledWith(expect.stringContaining(existingId))
-    } finally {
-      warn.mockRestore()
-    }
+    const before = store.getState().tabsByWorktree
+
+    expect(() => store.getState().createTab(wt, undefined, undefined, { id: existingId })).toThrow(
+      `Terminal tab ${existingId} already exists`
+    )
+    expect(store.getState().tabsByWorktree).toBe(before)
   })
 
   it('treats tab ids as global and rejects hints that collide in another worktree', () => {
@@ -93,14 +91,10 @@ describe('createTab tabId hint', () => {
       unifiedTabsByWorktree: {}
     })
 
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
-    try {
-      const tab = store.getState().createTab(wtA, undefined, undefined, { id: existingId })
-      expect(tab.id).not.toBe(existingId)
-      expect(warn).toHaveBeenCalledWith(expect.stringContaining(existingId))
-    } finally {
-      warn.mockRestore()
-    }
+    expect(() => store.getState().createTab(wtA, undefined, undefined, { id: existingId })).toThrow(
+      `Terminal tab ${existingId} already exists`
+    )
+    expect(store.getState().tabsByWorktree[wtA]).toBeUndefined()
   })
 
   it('ignores empty string hints instead of persisting an unusable tab id', () => {
diff --git a/src/renderer/src/store/terminals/terminal-tab-creation.ts b/src/renderer/src/store/terminals/terminal-tab-creation.ts
index 5e12d3b45a8..511498965d1 100644
--- a/src/renderer/src/store/terminals/terminal-tab-creation.ts
+++ b/src/renderer/src/store/terminals/terminal-tab-creation.ts
@@ -52,22 +52,20 @@ export function createTerminalTabCreationActions(
         const existing = (s.tabsByWorktree[worktreeId] ?? []).filter(
           (entry) => !orphanTerminalIds.has(entry.id)
         )
-        // Why: honor a caller-supplied tab id but mint on collision — aliasing two PTYs to one id corrupts agent-status routing. See docs/cli-terminal-hook-pane-key.md.
         // Why: only honor a non-empty trimmed hint; useIpcEvents spreads `id` whenever tabId !== undefined, so a stray '' would break paneKey routing.
         const trimmedHint = typeof options?.id === 'string' ? options.id.trim() : ''
         const hintedId =
           trimmedHint.length > 0 && isValidHostTerminalTabId(trimmedHint) ? trimmedHint : undefined
-        const idCollides =
+        // Why: the caller's PTY routes agent status by this id, so a fresh id would orphan it and aliasing would corrupt another tab's.
+        if (
           hintedId !== undefined &&
           Object.values(s.tabsByWorktree).some((tabs) =>
             tabs.some((entry) => entry.id === hintedId)
           )
-        if (idCollides) {
-          console.warn(
-            `[createTab] tabId hint ${hintedId} already exists; minting a fresh id (hook attribution will degrade for this terminal)`
-          )
+        ) {
+          throw new Error(`Terminal tab ${hintedId} already exists`)
         }
-        const id = hintedId !== undefined && !idCollides ? hintedId : createBrowserUuid()
+        const id = hintedId ?? createBrowserUuid()
         const requestedInitialLeafId =
           options?.initialLeafId && isTerminalLeafId(options.initialLeafId)
             ? options.initialLeafId