Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and clearly states read-only, public data, and no token requirement. It also describes the return format. It does not mention pagination or rate limits, but for a simple search tool this is sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.