Skill Creator frontmatter guidance conflicts with sample and validator

What happened?

The bundled Skill Creator sample appears to give conflicting guidance about allowed SKILL.md frontmatter fields.

At the top of the same sample skill, the frontmatter includes:

metadata:
  short-description: Create or update a skill

Later, the authoring guidance says:

Do not include any other fields in YAML frontmatter.

The bundled quick_validate.py script also explicitly allows additional frontmatter keys beyond name and description, including metadata, license, and allowed-tools.

Expected behavior

The Skill Creator guidance should align with the bundled sample and validator: either document the allowed optional frontmatter fields, or update the sample/validator if name and description are intended to be the only supported keys.

Additional context

I searched open issues and PRs for terms including skill-creator, metadata frontmatter, quick_validate, and allowed-tools, and did not find an existing open item that appears to cover this guidance conflict.