Revert "fix(core): guide agent to pivot to read-only tools when plan mode blocks"

packages/core/src/core/coreToolScheduler.test.ts

@@ -6239,9 +6239,7 @@ describe('CoreToolScheduler plan mode with ask_user_question', () => {
       expect(responseJson).toContain('"error"');
       expect(responseJson).toContain('Tool blocked by plan mode');
       expect(responseJson).toContain('write_file');
-      // Plan-required teammates get pivot-to-read-only then exit_plan_mode hint
-      expect(responseJson).toContain('Do NOT retry');
-      expect(responseJson).toContain('Pivot to read-only');
+      // Plan-required teammates get exit_plan_mode hint
       expect(responseJson).toContain('exit_plan_mode');
       expect(completedCalls[0].response.error).toBeInstanceOf(Error);
       expect(completedCalls[0].response.errorType).toBe(
@@ -6314,14 +6312,12 @@ describe('CoreToolScheduler plan mode with ask_user_question', () => {
       expect(completedCalls[0].status).toBe('error');
       if (completedCalls[0].status === 'error') {
         // SDK, subagent, and teammate paths all get the same error format
-        // but different guidance: SDK/subagents get "present your plan directly"
+        // but different guidance: SDK/subagents get "Present your plan directly"
         const responseParts = completedCalls[0].response.responseParts;
         const responseJson = JSON.stringify(responseParts);
         expect(responseJson).toContain('"error"');
         expect(responseJson).toContain('Tool blocked by plan mode');
-        expect(responseJson).toContain('Do NOT retry');
-        expect(responseJson).toContain('Pivot to read-only');
-        expect(responseJson).toContain('present your plan directly');
+        expect(responseJson).toContain('Present your plan directly');
         expect(responseJson).not.toContain('exit_plan_mode');
         expect(completedCalls[0].response.error).toBeInstanceOf(Error);
         expect(completedCalls[0].response.errorType).toBe(

packages/core/src/core/coreToolScheduler.ts

@@ -2467,10 +2467,9 @@ export class CoreToolScheduler {
                 `Tool blocked by plan mode: "${reqInfo.name}" is not a read-only tool. ` +
                   `Only read-only tools (read_file, grep_search, glob, list_directory, ` +
                   `web_fetch, etc.) are allowed in plan mode.` +
-                  ` Do NOT retry this tool. ` +
                   (isPlanRequiredTeammate
-                    ? `Pivot to read-only alternatives to gather the information you need, then call exit_plan_mode with a plan that covers this tool's purpose.`
-                    : `Pivot to read-only alternatives to gather equivalent information, then present your plan directly to the caller.`),
+                    ? ` Call exit_plan_mode to exit plan mode and execute this tool.`
+                    : ` Present your plan directly to the caller instead of executing this tool.`),
               );
               this.setStatusInternal(reqInfo.callId, 'error', {
                 ...createErrorResponse(

packages/core/src/core/prompts.test.ts

@@ -498,14 +498,6 @@ describe('getPlanModeSystemReminder', () => {
     expect(result).toContain('exit_plan_mode tool');
   });
 
-  it('should include guidance when a tool is blocked by plan mode', () => {
-    const result = getPlanModeSystemReminder();
-
-    expect(result).toContain('When a Tool is Blocked by Plan Mode');
-    expect(result).toContain('Do NOT retry');
-    expect(result).toContain('Pivot to read-only');
-  });
-
   it('should be deterministic', () => {
     const result1 = getPlanModeSystemReminder();
     const result2 = getPlanModeSystemReminder();

packages/core/src/core/prompts.ts

@@ -893,14 +893,6 @@ Start by quickly scanning a few key files to form an initial understanding of th
 - Reference existing functions and utilities you found that should be reused, with their file paths.
 - Include a verification section describing how to test the changes end-to-end.
 
-### When a Tool is Blocked by Plan Mode
-
-If a non-read-only tool is blocked:
-- Do NOT retry the blocked tool or repeatedly attempt similar non-read-only tools
-- Do NOT immediately call exit_plan_mode just to unblock it — continue gathering context with read-only tools first
-- Pivot to read-only tools (read_file, grep_search, glob, list_directory, agents) to gather the information the blocked tool would have provided
-- Once you have enough context to form a complete plan, call exit_plan_mode
-
 ### When to Converge
 
 Your plan is ready when you have addressed all ambiguities and it covers: what to change, which files to modify, what existing code to reuse (with file paths), and how to verify the changes. Present your plan ${planOnly ? 'directly' : `by calling the ${ToolNames.EXIT_PLAN_MODE} tool, which will prompt the user to confirm the plan`}. Do NOT make any file changes or run any tools that modify the system state in any way until the user has confirmed the plan.