[BUG] Agents Not Working : {"type":"error","error":{"type":"invalid_request_error","message":"tools: Tool names must be unique."}}

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?

Bug Report Information

Issue: Agent invocation fails with "tools: Tool names must be unique" error

Details:

• Error occurs when invoking ANY specialized agent (cads-refactoring, cads-architect, Explore, etc.)
• Error message: {"type":"error","error":{"type":"invalid_request_error","message":"tools: Tool names must be unique."}}
• Affects all agent types, not just specific ones
• Occurs consistently across multiple invocation attempts

To Report:
Please report this at: https://github.com/anthropics/claude-code/issues

Include:

• Error message: "tools: Tool names must be unique"
• Context: Attempting to use Task tool with any subagent_type
• Impact: Unable to use specialized agents for context/expertise management

What Should Happen?

Claude should successfully use the agents

Error Messages/Logs

Steps to Reproduce

1. Try and use any agent.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.30 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_