Creating custom agents with "/agent create" is broken

[simonis]

The documentation at https://kiro.dev/docs/cli/custom-agents/creating/ describes how to create a custom agent:

> /agent create

✔ Enter agent name:  · backend-specialist
✔ Enter agent description:  · You are a specialist in backend coding practices
✔ Agent scope · Local (current workspace)
Select MCP servers (use Space to toggle, Enter to confirm): markdown-downloader (node), code-analysis (uv)

✓ Agent 'backend-specialist' has been created and saved successfully!

But that constantly fails with:

✗ The LLM did not generate a valid agent configuration. Please try again.

[github-actions]

🤖 Potential Duplicate Detected

This issue appears to be similar to:

• #6457: Kiro CLI - agent create: invalid agent configuration (95% similar)
• #5710: Agent config with both hooks and toolsSettings fails to deserialize (85% similar)
• #4906: "/agent create -d path" can't work well (85% similar)
• #4793: Bug in /agent generate when copying mcp info (85% similar)

What happens next?

• ⏰ This issue will be automatically closed in 3 days
• 🏷️ If this is not a duplicate, you can prevent automatic closure by adding a comment or reacting with 👎 to this message.
• 💬 Comment on the original issue if you have additional information

Why is this marked as duplicate?
Both report the exact same problem with '/agent create' command failing with 'invalid agent configuration' error message