Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds valuable behavioral context beyond the annotations by disclosing that it never posts, sends, or publishes anything, and that the output is for human review. This is particularly useful given readOnlyHint=false, as it clarifies the true side-effect profile, though it does not cover storage or retrieval of drafts.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.