/compact fails with "tools: Tool names must be unique" error when using multiple MCP servers (v2.0.70)

[jasonKRR]

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?

When running /compact command after using MCP tools, it fails with the following error:

Error: Error during compaction: Error: API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"tools: Tool names must be unique"},"request_id":"req_011CWA8bntCcJpqrx7YyiUXN"}

Environment:

• Version: 2.0.70
• OS: Windows 11 (MINGW64)
• MCP servers: 6 (supabase, context7, shadcn, vercel, cloudflare-workers, chrome-devtools)

Notes:

• /mcp list shows no duplicate servers
• Error occurs consistently after using MCP tools (especially chrome-devtools)
• Starting a new conversation and running /compact also fails
• Removed duplicate MCP configs from .claude.json but issue persists
• This was supposedly fixed in v2.0.31 but still occurs in v2.0.70

What Should Happen?

/compact should successfully compact the conversation context without errors, even when multiple MCP servers are connected and MCP tools have been used in the conversation.

Error Messages/Logs

Steps to Reproduce

1. Connect 6 MCP servers (supabase, context7, shadcn, vercel, cloudflare-workers, chrome-devtools)
2. Start a new conversation
3. Use an MCP tool (e.g., chrome-devtools fill command)
4. When "Context low" warning appears, run /compact
5. Error occurs: "tools: Tool names must be unique"

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

2.0.70

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

No response