Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full disclosure burden, yet it says nothing about whether the comment is trashed or permanently destroyed, whether force is needed, what permissions are required, or whether replies are affected. The only behavioral hint (trash vs permanent) lives in the schema's force field, not the description.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.