Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), so the bar is lower. The description adds real behavioral context beyond that: headsetPolicy null clears the policy (a mutation side-effect), sourceUrl is REQUIRED when level=required, and rules must not be invented. It stops short of stating permission requirements or duplicate/ordering behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.