Default-enable.

packages/cli/src/config/config.test.ts

@@ -1867,6 +1867,32 @@ describe('loadCliConfig with admin.mcp.config', () => {
   });
 });
 
+describe('loadCliConfig deepValidation', () => {
+  beforeEach(() => {
+    vi.spyOn(ExtensionManager.prototype, 'getExtensions').mockReturnValue([]);
+  });
+
+  it('should enable deepValidation by default', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments(createTestMergedSettings());
+    const settings = createTestMergedSettings();
+    const config = await loadCliConfig(settings, 'test-session', argv);
+    expect(config.isDeepValidationEnabled()).toBe(true);
+  });
+
+  it('should allow disabling deepValidation via settings', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments(createTestMergedSettings());
+    const settings = createTestMergedSettings({
+      general: {
+        deepValidation: false,
+      },
+    });
+    const config = await loadCliConfig(settings, 'test-session', argv);
+    expect(config.isDeepValidationEnabled()).toBe(false);
+  });
+});
+
 describe('loadCliConfig model selection', () => {
   beforeEach(() => {
     vi.spyOn(ExtensionManager.prototype, 'getExtensions').mockReturnValue([]);

packages/cli/src/config/config.ts

@@ -900,7 +900,7 @@ export async function loadCliConfig(
     memoryBoundaryMarkers: settings.context?.memoryBoundaryMarkers,
     importFormat: settings.context?.importFormat,
     debugMode,
-    deepValidation: settings.general?.deepValidation,
+    deepValidation: settings.general?.deepValidation ?? true,
     question,
     worktreeSettings,
 

packages/cli/src/config/settingsSchema.ts

@@ -241,7 +241,7 @@ const SETTINGS_SCHEMA = {
         label: 'Deep Validation',
         category: 'General',
         requiresRestart: false,
-        default: false,
+        default: true,
         description:
           'Run a subagent after the main agent finishes to perform final validation.',
         showInDialog: true,