claude.ai Gmail MCP connector requests insufficient OAuth scopes — cannot read emails

Bug

The claude.ai Gmail MCP connector authenticates successfully (shows \"Connected\") but all read operations fail with:

Request had insufficient authentication scopes.

Steps to reproduce

1. Enable claude.ai Gmail via /mcp
2. Complete OAuth flow
3. Try any search/read tool (e.g. search_threads)
4. Get \"insufficient authentication scopes\" error

Expected

Gmail read permissions are requested during the OAuth flow so that tools like search_threads and get_thread work.

Actual

Connection succeeds and shows \"Connected\" but no read scopes are granted to the token. Reconnecting via the Reconnect button does not trigger a new OAuth consent screen, so there is no way to fix the scopes without revoking the token from Google's side (myaccount.google.com/permissions).

Even after revoking the Google authorization and re-enabling the connector, the local MCP cache still considers the session valid and no new OAuth consent screen is shown.

Environment

• Claude Code CLI (VSCode extension)
• Platform: Linux