Earliest supported layer
Rules distinguish availability, discovery, parsing, configuration, dependency, connection, authentication, registration, exposure, activation, authorization, execution, and persistence.
Codex capability diagnosis
Why is this MCP server not working in Codex?
Paste the first MCP startup, initialize, auth, tool-list, or invocation error—not an entire log.
1 · Redacted on this device
2 · Matched to explainable rules
3 · Saved only when you choose
Result
Your first supported failing layer will appear here
Capability Doctor will either return a bounded diagnosis, show the exact evidence still needed, or stop at an honest unknown.
Method and limits
A capability chain, not an AI guess
Evidence before verdict
A rule must meet a deterministic threshold. Conflicting or incomplete evidence becomes partial or unknown; it is not converted into a confident root cause.
No unknown execution
The site does not install capabilities, execute packages, contact private endpoints, edit configuration, or ask for credentials.
Private by explicit choice
A diagnosis is stateless by default. Saved reports use random URLs, expire after seven days, can be deleted immediately, and are excluded from indexing.