{"name":"url_check","intro":"Actually fetch a URL and report what happened: final status, the redirect chain, the URL you ended up at, content type, size and latency. A `HEAD` by default, falling back to `GET` when a server rejects it.\n\nOnly public `http`/`https` addresses are fetched. The host is resolved and judged *before* a connection is opened, and again after every redirect — a public host is free to answer `302 http://169.254.169.254/`, which on a cloud instance is the metadata service and answers with credentials. Loopback, link-local, private (RFC 1918), unique-local, reserved and metadata addresses are refused with `invalid_input` naming what the name resolved to. Any other scheme — `file:`, `ftp:`, `data:` — is refused rather than rewritten.","when_to_use":["Before telling a user a link works — models are confident about dead URLs.","Checking where a shortened or tracking link actually lands.","Not for reading the page: this reports on the response, not its body."],"network":true,"related":"[`validate`](/docs/tools/validate) with `mode: url` checks the *syntax* of a URL without fetching it.","docs_url":"/docs/tools/url_check","parameters":[{"name":"url","type":"string","required":true,"doc":"The URL to fetch. A bare host is assumed to be `https://`; only public http(s) addresses are fetched.","default":null},{"name":"method","type":"string","required":false,"doc":"`HEAD` or `GET`.","default":"`HEAD`"}]}