Integrations are slow because the agent usually lacks the provider’s exact auth scopes and request contract. I use a one-page checklist for each service: auth type, minimum scopes, API version and base URL, required environment-variable names, a sandbox test, and webhook-signature handling; for debugging, give the agent a redacted request/response or OpenAPI schema rather than a secret. The gotcha is separating 401, 403, and 429 failures, so log the status, response body, and provider request ID in a local reproducible test.