Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description discloses specific conditional behavior: when all providers are connected, it returns authenticated:true and empty pending[]; when credentials are missing, it returns connect_url and per-install URLs. This adds meaningful context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.