diff --git a/src/errors.ts b/src/errors.ts
index 7883799..25ecadd 100644
--- a/src/errors.ts
+++ b/src/errors.ts
@@ -134,6 +134,13 @@ export function serverConnectionError(
   } else if (cause.includes('ETIMEDOUT') || cause.includes('timeout')) {
     suggestion =
       'Connection timed out. Check network connectivity and server availability';
+  } else if (
+    cause.includes('already running') ||
+    cause.includes('profile is locked') ||
+    cause.includes('Use --isolated')
+  ) {
+    suggestion =
+      'This looks like a stateful server reusing a locked profile. Keep daemon mode enabled so mcp-cli can reuse the same server connection, and only use --isolated when you intentionally want a separate fresh instance.';
   } else if (cause.includes('401') || cause.includes('Unauthorized')) {
     suggestion = 'Authentication required. Add Authorization header to config';
   } else if (cause.includes('403') || cause.includes('Forbidden')) {
diff --git a/tests/errors.test.ts b/tests/errors.test.ts
index dab1e0d..13bb176 100644
--- a/tests/errors.test.ts
+++ b/tests/errors.test.ts
@@ -120,6 +120,16 @@ describe('errors', () => {
       const error = serverConnectionError('remote', '401 Unauthorized');
       expect(error.suggestion).toContain('Authorization header');
     });
+
+    test('serverConnectionError detects stateful server profile lock hints', () => {
+      const error = serverConnectionError(
+        'chrome-devtools',
+        'The browser is already running for /tmp/chrome-profile. Use --isolated to run multiple browser instances.',
+      );
+      expect(error.suggestion).toContain('daemon mode');
+      expect(error.suggestion).toContain('--isolated');
+      expect(error.suggestion).toContain('same server connection');
+    });
   });
 
   describe('tool errors', () => {