How to check if your site is agent-ready (free tools)

https://isitagentready.com/check?url=https://yoursite.com

Paste that URL in a browser. In under ten seconds you get a score out of 100 and a list of exactly what is broken. This post explains what each signal means and what to fix first.

Why "agent-ready" is not the same as "SEO-friendly"

Search crawlers want indexable HTML. AI agents want something different:

• A machine-readable summary of what the site does (llms.txt at the root)

• A structured list of available endpoints or tools (/.well-known/api-catalog)

• Auth instructions an agent can parse without reading a docs page (auth.md)

• Clean semantic HTML with no token-wasting layout wrappers

A site can rank on page one of Google and still be completely opaque to a Claude or Codex agent trying to call it.

The free checker: isitagentready.com

Paste any URL into isitagentready.com and get a score out of 100 across four signal groups.

Scores under 50 mean an agent will either skip the site or hallucinate its capabilities. Scores above 80 mean the site can be wired into an agent workflow with minimal prompt engineering.

What each failing signal costs you

Missing llms.txt

Without it, a language model parsing your site has to infer structure from HTML — slow, token-heavy, and error-prone. Fix:

# /llms.txt
# yoursite.com

> One-line description of what this site does.

## Key pages
- [Home](https://yoursite.com/): main entry point
- [API docs](https://yoursite.com/api/): endpoint reference
- [Pricing](https://yoursite.com/pricing/): licensing terms

Drop that file at your domain root. The checker re-scores immediately.

Missing /.well-known/api-catalog

Agents discovering what a site can do look here first. A minimal catalog:

{
  "apis": [
    {
      "id": "main",
      "title": "Your API",
      "baseUrl": "https://yoursite.com/api/",
      "specUrl": "https://yoursite.com/openapi.json"
    }
  ]
}

No auth signal

An agent that hits a 401 with no WWW-Authenticate header or auth.md file will stall. Add a header:

WWW-Authenticate: Bearer realm="https://yoursite.com/auth.md"

Then put human-readable and machine-readable auth instructions in /auth.md.

x402 for paid endpoints

If any endpoint requires payment, return a proper HTTP 402 with an x402 challenge rather than a 401 or an HTML paywall. An agent can read the challenge, discover the price, and settle on-chain — no human in the loop. Without it, the agent stops dead.

Reading your MCPize grade alongside the agent-readiness score

MCPize grades MCP servers specifically — it checks tool schema quality, transport compliance and error handling, graded A+ to B+. The agent-readiness checker covers the broader site surface: discovery, auth, and API legibility.

Run both. A server that grades A+ on MCPize but sits at 40/100 on isitagentready.com is reachable by a developer who already knows the endpoint URL, but invisible to an agent discovering it cold.

Fix order

Three things move the score the most, in this order:

1. Add llms.txt — 15–20 point jump for most sites, takes under ten minutes

2. Add /.well-known/api-catalog — unlocks the API surface score entirely

3. Fix auth signalling — auth.md plus correct WWW-Authenticate headers

JavaScript-rendered content, missing alt text, and thin heading structure matter, but are lower-leverage unless the site is a single-page app with no server-rendered HTML.

Next step

Run the checker on your own domain:

https://isitagentready.com/check?url=https://yourdomain.com

If the API surface score is zero, /.well-known/api-catalog is the fastest fix. If discoverability is the gap, start with llms.txt. The checker tells you exactly which line to address — no guessing required.