Has .md or .mdx mirror
A markdown mirror at <page>.md is the cleanest format an agent can ingest — no HTML, no scripts, no styling, just the content. Mirrors are a small amount of work to generate but dramatically reduce the cost of ingesting a doc site.
How the check decides
The check derives a markdown URL by stripping any trailing slash and .html from the page path and appending .md, then .mdx. It sends a HEAD request and asserts a 2xx response. Fails if neither variant returns 2xx.
How to implement it
Add a build step that emits a markdown version of every page alongside the HTML. Most modern SSGs already have an “export markdown” plugin or expose the source markdown directly via a route. The mirror should match the HTML page’s URL with a .md extension.
Pass
GET /docs/install.md → 200 OK
Fail
GET /docs/install.md → 404 Not Found
GET /docs/install.mdx → 404 Not Found