Markdown mirror has required frontmatter
Frontmatter on the markdown mirror is metadata that doesn't have to be parsed out of the body. Agents read the title, description, doc_version, and last_updated fields to index, deduplicate, and trend the page over time.
How the check decides
The check fetches the markdown mirror, parses its YAML frontmatter with gray-matter, and asserts every one of title, description, doc_version, and last_updated is present. Fails (with the missing keys) if any are absent. Returns N/A if no mirror was published at all.
How to implement it
When you generate the markdown mirror, include a YAML frontmatter block at the top with the four required keys. Most SSGs already have a title and description for each page; doc_version is the docs/product version this page documents and last_updated is the source-file mtime in ISO 8601.
Pass
---
title: Install a14y
description: Install a14y in under a minute and audit your first site.
doc_version: "0.2"
last_updated: 2026-04-01
---
# Install a14y
...
Fail
---
title: Install a14y
---
# Install a14y
...