write-frontmatter-description

The model MUST write frontmatter descriptions following these rules.

Formatting Rules

1. Single-line only — Never use YAML multiline indicators (>-, |-, >, |)
2. No colons — Avoid colons (:) as they trigger YAML quoting. Rephrase or substitute.
3. Front-load critical info — First 1024 characters are most important
   • Claude Code may truncate to 1024 chars in some contexts
   • No hard limit, but keep key information in first 1024 chars
   • Convey purpose, triggers, and value early

Authoring Rules

These rules govern what the description must communicate — not just how it is formatted.

SOURCE: Anthropic skill-authoring best practices (docs.anthropic.com, accessed 2026-03-23)

1. Third-Person Phrasing