Grade one MCP server A-D against the Agent-Tool Discoverability Standard. Runs the LEGITIMATE MCP handshake (initialize + tools/list + one read-only tool call, all over POST JSON-RPC) and returns the grade, a per-criterion pass/evidence breakdown, and the single biggest gap to fix. This returns the grade and analysis ONLY — if you want a signed, portable certificate of the same audit, use verify_mcp_ready instead. DIRECTORY PRE-FLIGHT: these criteria cover the MECHANICAL reject reasons of the Claude Connectors Directory and ChatGPT Apps Directory (annotations, typed schemas, description clarity, liveness, graceful errors, anti-ghost) — run it before you submit. It does NOT cover privacy-policy, identity/business verification, OAuth callbacks, or prohibited-category rules; it catches mechanical failures, it does not guarantee a pass. Handshake only — no auth-bypass, no payment. Free. Best run against YOUR OWN server. (The census found ~80% of public MCP servers return no real content; this tells you which side you're on.)