Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the description is only obligated to add context. It does: the output is '~80% complete' and is intended for company secretary review, which is a genuinely useful quality/trust disclosure an agent would not get from the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.