[BUG] Gmail create_draft tool missing threadId parameter (regression from gmail_create_draft)

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?

Description
The create_draft tool in the Google Workspace Gmail integration is missing the threadId parameter that existed in the previous gmail_create_draft tool. This means drafts can no longer be created as in-thread replies — they all save as standalone new emails instead.

Previous behavior
The old gmail_create_draft tool accepted a threadId parameter. Passing a thread's ID caused the draft to be saved as a reply within that thread in Gmail.

Current behavior
The new create_draft tool has no threadId parameter. All drafts save as standalone emails with no thread association, regardless of subject line.

Steps to reproduce

1. Use the create_draft tool with a threadId field
2. Tool returns an error ("Tool execution failed")
3. Without threadId, draft saves as a new standalone email

Expected behavior
create_draft should accept a threadId parameter so drafts can be placed in-thread as replies.

Environment

• Claude Code with Google Workspace Gmail MCP integration
• Integration ID: d0ba6c0b-1d1c-4a8f-9e42-16fcf4984618

What Should Happen?

create_draft should accept a threadId parameter so drafts can be placed in-thread as replies.

Error Messages/Logs

Error: There's no runtime error message — the issue is a missing parameter. When Claude inspects the create_draft schema via ToolSearch, threadId simply isn't there. Any attempt to pass it fails with InputValidationError because the schema doesn't accept it.

Steps to Reproduce

Steps to replicate:

Connect the Gmail MCP server (Google Workspace connector) in Claude Code
Use ToolSearch to fetch the create_draft schema — confirm threadId is not listed as a parameter
Attempt to draft a reply to an existing email thread — the draft will appear as a new standalone email in Gmail, not as a reply inside the thread
Compare to the previous gmail_create_draft tool schema, which included threadId as a supported parameter
Expected behavior: create_draft should accept a threadId parameter so drafts can be created as in-thread replies, matching the behavior of the previous tool.

Impact: Any workflow that drafts customer support replies (or any replies) using the Gmail MCP server produces standalone emails that are disconnected from the original thread — requiring manual copy-paste to fix before sending.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

claude code sonnet 4.6

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_