[BUG] Gmail connector OAuth missing write/modify scopes for label operations

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The Gmail connector's OAuth flow should request the gmail.modify scope (or equivalent) so that all exposed tools — including label_thread and label_message — work correctly. If a tool requires a scope that isn't currently granted, either the scope should be added to the OAuth request, or the tool should not be exposed in the UI.

What Should Happen?

The Gmail connector's OAuth flow should request the gmail.modify scope (or equivalent) so that all exposed tools — including label_thread and label_message — work correctly. If a tool requires a scope that isn't currently granted, either the scope should be added to the OAuth request, or the tool should not be exposed in the UI.

Error Messages/Logs

This connector requires additional permissions. The user needs to reconnect it with the appropriate access.

Steps to Reproduce

1. Open Cowork mode in Claude Desktop
2. 2. Connect the Gmail connector
3. 3. Search for email threads using search_threads — this works fine (read access is granted)
4. 4. Attempt to apply a label to a thread using label_thread
5. 5. Observe error: "This connector requires additional permissions. The user needs to reconnect it with the appropriate access."
6. 6. Disconnect, delete, and reconnect the Gmail connector
7. 7. Check Google's third-party access permissions screen — only "See your profile info", "Manage drafts and send emails", and "View your email messages and settings" are listed. No modify/write scope for labels.
8. 8. Retry label_thread — same error persists

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Cowork mode (Claude Desktop) — April 2026

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This bug was encountered in Cowork mode (not Claude Code CLI). The label_thread and label_message tools appear to have been recently added to the Gmail connector, but the OAuth app registration was not updated to include the gmail.modify scope. Screenshot of Google's third-party permissions screen confirms only read + drafts/send scopes are granted. The Terminal/Shell field above is not applicable — this is a Cowork desktop issue.