[BUG] Create new agent - Invalid agent configuration generated

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?

Create new agent always fails with error: Invalid agent configuration generated

What Should Happen?

Sub-agent should be created

Error Messages/Logs

Invalid agent configuration generated

Steps to Reproduce

/agents 
❯ Create new agent


│ Create new agent                                                                                                                                                                                              
│ Choose location                                                                                                                                                                                               
│ ❯ 1. Project (.claude/agents/)  

│ Create new agent                                                                                                                                                                                              
│ Creation method                                                                                                                                                                                               
│ ❯ 1. Generate with Claude (recommended)  

Create new agent                                                                                                                                                                                              
│ Describe what this agent should do and when it should be used (be comprehensive for best results)  
| any agent prompt fails here

Invalid agent configuration generated

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.1

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_