Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=false), the description discloses the human-in-the-loop approval flow, that granted access propagates to the whole account including all agents, and that re-asking updates rather than duplicates the pending request. These are non-obvious behavioral traits an agent needs.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.