Domain 3Skills, Plugins & Connectors
YAML Frontmatter
TL;DR
The metadata block at the top of a SKILL.md file, placed between triple-dash markers (---).
Definition
The metadata block at the top of a SKILL.md file, placed between triple-dash markers (---). It contains the skill's name, version number, description, and trigger conditions. Without this frontmatter, Claude cannot discover, trigger, or load the skill — it is completely invisible.
Exam Context
A skill without YAML frontmatter does not work with "reduced functionality" — it does not work at all. The frontmatter is mandatory, not optional.