Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral disclosure burden. It partially fulfills this by specifying the returned fields and implying a read-only list operation. However, it does not disclose pagination, ordering, completeness, authentication requirements, or other potential behavioral traits.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.