Skill Frontmatter
Claude CodeDefinition
YAML configuration at the top of a Claude Code skill file (SKILL.md) that controls how the skill is triggered and executed. Key fields: 'description' (natural language trigger for automatic activation), 'allowed-tools' (whitelist of permitted tools), 'context' (fork/current/none).
Example Usage
Set description: 'when asked to review code for security vulnerabilities' so Claude automatically applies the skill without requiring explicit invocation.