Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden and discloses useful traits: no authentication is required, the result is limited to the top 300 wallets, and data is cached for 2 minutes. It does not describe return fields or error behavior, but the auth and caching details are the most important operational facts for this read endpoint.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.