[Bug] Invalid Markdown Frontmatter: Unresolved Link Reference `[function_code]`

Bug Description

Claude generated an agent that contains [function_code] (without the backticks) in its front-matter. I haven't read the Markdown (GFM?) spec, but looks like just like in Markdown body text, [function_code] expects a (url) next to it. So this seems to be invalid Markdown:

Environment Info

• Platform: linux
• Terminal: kgx
• Version: 1.0.120
• Feedback ID: b518fee4-bd46-42f8-a59c-5b38d2bfccf6

Agent front matter:

---
foo bar assistant: "Here's the implementation: [function code]"
---