[BUG] claude.ai Gmail MCP create_draft rewrites plain-text body URLs into corrupted google.com/url redirect wrappers

Summary

create_draft on the claude.ai Gmail MCP connector rewrites every URL in a plain-text body into a Gmail redirect wrapper (https://www.google.com/url?q=...&source=gmail&ust=...&sa=E), and the wrapper itself comes back corrupted (a control character where ust= should be). Drafts that should contain clean literal URLs instead contain mangled redirect links, visible both in the Gmail composer and in list_drafts output.

Reproduction

1. Call mcp__claude_ai_Gmail__create_draft with only to, subject, and a plain-text body (no htmlBody):

body: "Bare URL test: dioro.com/pages/affiliates and https://www.example.com/path here."

1. Call mcp__claude_ai_Gmail__list_drafts and read the new draft's plaintextBody.

Observed

Bare URL test: https://www.google.com/url?q=http://dioro.com/pages/affiliates&source=gmail&ust^W81160120613000&sa=E and https://www.google.com/url?q=https://www.example.com/path&source=gmail&ust^W81160120613000&sa=E here.

Notes:

• Even schemeless text like dioro.com/pages/affiliates is linkified and wrapped.
• The ust parameter is corrupted: U+0017 appears where = (and the first digit) should be, so the redirect URLs are not even well-formed.
• The same wrapping appears in drafts created by the connector in earlier sessions, so it is systematic, not a one-off.

Expected

A draft created with a plain-text body should store the text verbatim as text/plain, as a direct Gmail API users.drafts.create call with a text/plain MIME part does. No linkification, no redirect wrapping.

Impact

Any draft composed through the connector that contains a URL is unusable as-is; the user has to retype or re-paste the links manually before sending. Since the wrapper is also malformed, sent messages may carry broken links.

Environment

• claude.ai Gmail MCP connector (mcp__claude_ai_Gmail__*) used from Claude Code CLI on macOS (darwin 24.3.0)
• Observed 2026-06-10