Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnlyHint and openWorldHint annotations, the description discloses that results are capped at five, ordered nearest or best matching first, and include care type, listed services, a phor.me page, and an appointment-request link. It also explicitly states what the tool does not do: diagnose, treat, show prices, or book.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.