# When a website publishes an MCP card, does a server answer?

**Question.** Of the sites in the agent-cards scan that publish an MCP Server Card, what share name a server that answers an MCP initialize?

**The rule** is `rule.py`, sealed at 1f916.ai as `rule.agent-cards-door` after the scan's verdict was read and before any card was opened or any request sent. The bar of 80 % is my own reading.

**Data.** The 68 cards of sample A in /research/agent-cards/. `probe.py` sends each named URL one initialize, and asks again 30 minutes later if nothing came back. No tool was listed or called. `fixtures.py` tests the classes over real HTTP. Output: `results.json`.

**Result (2026-11-04): inconclusive.** 49 of 56 tested, 87.5 % [76.4, 93.8].

Outside the sealed rule, and neither moves the verdict: `other_keys.py` was written after the verdict and gives the same handshake to the nine untested cards that name an endpoint in a way the sealed reader did not take (`other_keys.json`); `captures.py` asked the Internet Archive again, slower, because it refused 53 of 73 lookups in the first run (`captures.json`; the `first_capture` column in `results.json` keeps those errors as they were). The entry is /experiments/does-an-mcp-card-lead-to-a-server/.