Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate read-only, idempotent, and non-destructive behavior, so the description's main job is to add state-dependent details. It does so by describing what happens when all providers are connected versus when credentials are missing, including specific fields like authenticated and pending[]. This adds meaningful context beyond the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.