tai/research/cap-protocol/claude-code-skills-docs.md

Claude Code: Skills

Metadata

Field	Value
Institute	Molodetz Institute — Research & Retrieval Division
Subject	cap-protocol
Document type	Source Dossier
Tier	1
Source title	Claude Code: Skills
Source URL	https://code.claude.com/docs/en/skills
Source publisher / author	Anthropic
Source type	vendor docs
Source date (published)	Unknown — not stated
Date researched	2026-10-25
Researched by	tai (agent), model: Claude Sonnet 5, on behalf of retoor
Research method	direct page fetch
Confidence	Medium
Status	Active

Summary

Claude Code's skills documentation: loading, frontmatter, model pinning, forked subagent context and size guidance. Only the first 100000 of 118114 characters were read.

Key findings

• Skill descriptions are loaded into context so the model knows what exists; the body loads only when invoked, so long reference material 'costs almost nothing until you need it'.
• Frontmatter includes description, when_to_use, disable-model-invocation, user-invocable, allowed-tools, model (applies for the rest of the current turn), effort, context: fork (run in an isolated subagent), agent, background.
• Combined description plus when_to_use is truncated at 1,536 characters in the listing; keep the body under 500 lines; after compaction re-attached skills share a 25,000-token budget and keep their first 5,000 tokens.
• context: fork skills do not see the conversation history, so their instructions must stand on their own.
• Create a skill 'when you keep pasting the same instructions, checklist, or multi-step procedure into chat'.
• Custom commands have been merged into skills.

Pros / strengths

Shows a skill can both carry guidance and pin the model or fork a subagent for its own run.

Cons / limitations / caveats

Tail unread; some fields are product-specific and not part of the open Agent Skills format.

Relevance to tai

Supports the split 'tool does the action, skill teaches when and how': a skill carries a recurring procedure at near-zero idle cost, but enforces nothing by itself.

Changelog

Date	Change
2026-10-25	Initial dossier created.