Elpais · Agent Readiness · Agent Checker

Discoverability

Can agents find your site and its capabilities?

failWebMCP / agent-protocol tools discoveredAgent manifests

The page registers no tools via the WebMCP browser API (navigator.modelContext).

Fix: Expose your actions to AI agents with the WebMCP browser API: register tools via navigator.modelContext.registerTool. Optionally also publish a /.well-known/webmcp.json tool catalog as a discovery signpost.

warnKey pages discoveredKey pages crawl

Discovered 12 candidate pages but none were reachable.

Fix: Make sure the pages linked from your sitemap and navigation return HTTP 200 to non-browser clients — agents fetch them the same way our crawler does.

infoWebsite platformplatform

Could not identify a known website platform (custom stack or unrecognised).

Understanding

Can agents understand your content?

failHTML readiness checks ranStructured data & HTML

Homepage returned 403 — couldn't analyse structure.

warnMarkdown content negotiationOpen agent protocols

Homepage returned 403 for Accept: text/markdown.

warnHomepage content is server-renderedCrawlability (Google)

Homepage returned 403.

Operability

Can agents actually operate the page?

failWebMCP tools registered with the browserWebMCP tools

The page registers no tools via the navigator.modelContext browser API, so an AI agent has no structured way to operate it.

Fix: Expose your site’s actions to AI agents with the WebMCP browser API: call navigator.modelContext.registerTool({ name, description, inputSchema, execute }) from your page so an agent can invoke them. Implement it directly, or with a library like the @mcp-b polyfill (https://mcp-b.ai). Spec: https://github.com/webmachinelearning/webmcp.

passAccessibility tree is agent-navigableAccessibility

All 3 agent-critical accessibility audits passed — an agent can perceive and operate the page through its accessibility tree.

pass`[aria-hidden="true"]` is not present on the document `<body>`Accessibility

`[aria-hidden="true"]` is not present on the document `<body>` passed.

passDocument has a `<title>` elementAccessibility

Document has a `<title>` element passed.

pass`<frame>` or `<iframe>` elements have a titleAccessibility

`<frame>` or `<iframe>` elements have a title passed.

passOverall accessibility scoreAccessibility

Lighthouse accessibility score: 94/100. Agents read the page through its accessibility tree, so this is a proxy for how navigable your site is to an AI agent.

passCumulative Layout ShiftPerformance

0.070 (field data from CrUX) — good.

passTime to First BytePerformance

311ms (field data from CrUX) — good.

infoTool catalog signpost publishedWebMCP tools

No tool catalog was found at /.well-known/webmcp.json (or /.well-known/webmcp). The catalog is a community convention, not part of the WebMCP standard, so this does not affect WebMCP presence.

Fix: Consider also publishing a tool catalog at /.well-known/webmcp.json: a JSON document with a "spec" of "webmcp/0.1" and a "tools" array, where each tool declares a name and a clear description. It is a community convention (optional, not part of the WebMCP standard) that lets crawlers and agents discover your tools without executing JavaScript.

Trust & Security

Can agents safely transact?

failHTTP Strict-Transport-Security headerSecurity & trust

No Strict-Transport-Security header on the homepage.

Fix: Add `Strict-Transport-Security: max-age=15768000; includeSubDomains` so browsers and agents refuse to downgrade to http for at least six months.

warnOAuth authorization server metadataOpen agent protocols

/.well-known/oauth-authorization-server returned 404.

Fix: Publish /.well-known/oauth-authorization-server so AI agents discovering your OAuth setup can negotiate flows automatically. Required if your site offers an authenticated API.

warnOAuth protected-resource metadataOpen agent protocols

/.well-known/oauth-protected-resource returned 404.

Fix: Publish /.well-known/oauth-protected-resource so AI agents discovering your OAuth setup can negotiate flows automatically. Required if your site offers an authenticated API.

warnWeb Bot Auth signature headerOpen agent protocols

Homepage returned 403.

warnContent-Security-Policy headerSecurity & trust

No Content-Security-Policy header on the homepage.

Fix: Add a Content-Security-Policy. Even a strict default-src directive cuts XSS blast radius dramatically. Start in report-only mode to find violations.

warnHomepage shows no error outputSecurity & trust

Homepage returned 403 — couldn't scan for error markers.

warnNo mixed-content referencesSecurity & trust

Homepage returned 403 — couldn't scan for mixed content.

warnReferrer-Policy headerSecurity & trust

No Referrer-Policy header on the homepage.

Fix: Add `Referrer-Policy: strict-origin-when-cross-origin` so outbound links don't leak full URLs (including query strings) to third parties.

warnMIME-sniff protectionSecurity & trust

No `X-Content-Type-Options: nosniff` header.

Fix: Add `X-Content-Type-Options: nosniff` to prevent browsers (and some agents) from re-interpreting your responses as a different content type.

warnClick-jacking protectionSecurity & trust

No X-Frame-Options header and no CSP frame-ancestors directive.

Fix: Add `X-Frame-Options: SAMEORIGIN` (or a CSP frame-ancestors directive) to prevent your site being framed by a phishing host.

passSite is served over HTTPSSecurity & trust

Homepage scheme is https:.

passhttp:// redirects to https://Security & trust

http://elpais.com → https://elpais.com/ (1 hop).

passTLS certificate is not near expirySecurity & trust

Valid for 62 more days (Sep 22 09:54:50 2026 GMT, issuer: YR1).

passNo tech-stack disclosure in headersSecurity & trust

Server / X-Powered-By headers don't leak product version.