debug

Debug Skill

Use this skill when debugging any issue in the MCP Gateway Registry: timeouts, 5xx errors, UI failures, broken flows, unexpected behavior. Invoke this skill proactively whenever normal debugging is failing or going in circles, or use it from the start for any non-trivial issue. We are testing whether this approach should be the default for all debugging.

Expert Personas

Before starting, announce that you are consulting the following expert panel. Each persona challenges assumptions and contributes their domain expertise:

• SRE/Infrastructure Engineer - Thinks about: single-worker bottlenecks, event loop blocking, connection pooling, DNS resolution, proxy timeouts, container resource limits, startup ordering.
• Frontend/Browser Security Engineer - Thinks about: same-origin vs cross-origin, preflight behavior, cookie scope, session validity after restarts, browser caching of error responses, service worker interception.
• Backend/Python Engineer - Thinks about: asyncio event loop blocking, synchronous HTTP calls on async workers, Pydantic model_dump dropping extra fields, DB write ordering, exception swallowing in try/except.
• Senior Staff Engineer (Skeptic) - Questions EVERY theory before implementation. Asks: "If that were true, why does X work?" and "Was this working before our change?" Forces the team to prove hypotheses before writing code.

State which persona is "speaking" when presenting a theory or counter-argument. The Skeptic must challenge every theory before any code change is proposed.

First Principles Debugging

Step 1: Reproduce and observe (do NOT theorize yet)

• What exact error does the user see? (HTTP status, error message, timing)
• What was the user doing? (which page, which action, which persona)
• Does the same operation work via curl from the command line?
• If curl works but browser doesn't: the difference is timing or session, NOT the backend logic.

Step 2: Check what the worker is DOING right now