unknown-field

YAML frontmatter validation for SKILL.md files checks mandatory fields (name and description) while gracefully ignoring extra non-standard keys. This ensures accurate skill discovery without breaking when unexpected metadata is present at the root.

During skill discovery, unknown frontmatter keys are ignored without causing parsing errors. The system reads the root YAML, validates the required name and description fields exist, and safely bypasses any additional non-critical metadata.

Parsing root YAML frontmatter extracts mandatory fields and reports dependencies as an empty array when no scripts are present. This satisfies parsing requirements by focusing on critical keys and ignoring non-essential metadata.

A strict YAML schema is not required to validate mandatory frontmatter fields. The validation specifically enforces the presence of name and description at the root, allowing other unknown fields to pass through without triggering errors.

Custom metadata in SKILL.md frontmatter does not break discovery. The validation process applies graceful handling for additional non-standard fields, ensuring the system still recognizes and loads core information accurately.

Ignoring unknown fields in frontmatter validation means non-critical keys are bypassed entirely. If those extra fields contained necessary operational data, they would not be parsed during discovery, as the system only enforces mandatory name and description fields.