unknown-field

YAML frontmatter validation can preserve extra fields by enforcing mandatory name and description entries while accepting non-standard metadata keys alongside them. This keeps skill files valid during discovery workflows.

Skill parsing fails on custom metadata when validators strictly reject unknown YAML frontmatter keys. You need a tolerance mechanism that accepts non-standard fields while still enforcing required name and description entries.

You can include custom keys in SKILL.md frontmatter and keep the skill valid by using validation that accepts extra metadata fields. This ensures files remain compatible for packaging and discovery without rejecting author-defined keys.

The best way to check skill metadata files is applying YAML parsing that enforces mandatory name and description fields while preserving unknown frontmatter keys. This validates structure without discarding author-defined metadata.

Frontmatter validation supports non-standard YAML fields for skill discovery by checking required entries while ignoring extra keys. This allows skill authors to add optional metadata like ownership or versioning safely.

Allowing unknown fields in skill frontmatter lacks strict schema enforcement for custom keys, meaning invalid data types in extra metadata fields will not be caught. Validation focuses only on mandatory name and description entries.