MCP Queen probes every remote server in the official Model Context Protocol registry on a continuous cycle. This report is generated from 43,320 live probes of 9,326 remote servers, plus registry metadata for the full corpus. Every number is reproducible from the public API and the published dataset (CSV, 9,326 rows). Nothing here is self-reported.
The headline numbers
18,849 servers in the official MCP registry (18,650 marked active).
9,312 (49.9%) advertise a remote endpoint. The other 9,338 are local-install only (npx/uvx/docker): half the registry cannot be used without pulling code onto your machine.
Of the 9,326 remotes we grade, 7,723 (82.8%) are reachable right now. 1,603 (17.2%) are dead: they advertise an endpoint that does not answer. Roughly one in six "live" MCP servers is not.
Grades
Grade
Servers
Share of graded
A
4,956
53.1%
B
143
1.5%
C
1,501
16.1%
D
918
9.8%
F
1,808
19.4%
Grading is deterministic: reachability 25, protocol compliance 15, tooling quality 35, latency 10, provenance 15, and every point carries the verbatim observation that earned it. 29.2% of graded servers land at D or F, almost entirely on dead endpoints, broken initialize handshakes, or empty tool catalogs.
Authentication
5,201 servers (55.8%) are open: no auth required.
1,882 (20.2%) are auth-gated and well behaved: they reject unauthenticated calls with proper protocol semantics.
640 (6.9%) are auth-bare: they demand credentials but fail the rejection handshake itself, so a client cannot even discover how to authenticate correctly.
2,522 servers (27.0%) are graded provisional because auth gates their tooling: their advertised capabilities cannot be independently verified.
Tooling: the strongest part of the ecosystem
Across servers that answer tools/list, we have cataloged 102,013 tools from 5,241 servers (about 19 tools per server). Quality among servers that respond is high: 99.7% of cataloged tools ship a typed input schema and 99.5% carry a real description. The ecosystem's problem is not tool quality. It is that a large minority of servers cannot be reached or introspected at all.
Latency
Median round-trip for a reachable server: 233 ms. Open servers respond faster on average than auth-gated ones (336 ms vs roughly 480 ms mean).
What this means
Listing is not verification. Half the registry is local-only, a sixth of the remotes are dead, and a quarter of graded servers hide their capabilities behind auth. A registry entry tells you a server existed once; a probe tells you it works now.
The floor is low but the ceiling is high. The A-grade majority shows that a well-behaved remote MCP server is not hard to run. The 29% D/F tail is operational neglect, not technical difficulty.
Agents need freshness. Grades here churn daily as servers die and recover. Point-in-time directories go stale in days; continuous probing is the only honest signal.
Method, rubric, and per-server evidence: the evidence registry. MCP Queen is built by Health AI, the team behind the Constat and Clarity evidence servers.