Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the behavioral burden, and it does disclose the returned content and implies a read-only lookup via 'Read this'. It does not state the return format, whether the source/date values are cached or live, or any access constraints. Adequate but not rich for a metadata call.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.