Skill Frontmatter
context: fork, allowed-tools and argument-hint.
Why Frontmatter Matters
In Claude Code, a skill lives under .claude/skills/ and packages a reusable workflow. The body holds the instructions; the YAML frontmatter at the top configures how the skill executes.
Three frontmatter keys do most of the architectural work:
context: fork— isolate verbose output from your main session.allowed-tools— restrict which tools the skill may use.argument-hint— document the expected input.
Getting these right is the difference between a tidy, least-privilege skill and one that floods your context window or runs tools it never should.
Anatomy of a Skill File
A skill is a markdown file. The fenced YAML block at the very top is the frontmatter; everything below is the prompt Claude follows.
Note the distinction from the older .claude/commands/ directory (legacy) — .claude/skills/ is the current home. Both share project scope via VCS, while a copy under ~/.claude/ is personal and not shared with teammates.
---
name: audit-deps
description: Scan dependencies for known CVEs and summarize risk
context: fork
allowed-tools: Read, Grep, Glob, Bash
argument-hint: <package-name> [--severity high]
---
Audit the project's dependencies. If a package name is
provided as $ARGUMENTS, focus on that package; otherwise
scan all manifests. Report only HIGH and CRITICAL findings.