Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide readOnlyHint=true, so the description adds little beyond stating it gets information. It does not describe any behavioral traits such as response format, potential delays, or limitations. Given annotations exist, the bar is lower but the description should still add context like what fields are returned.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.