Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, indicating safe operation. The description adds behavioral details: weights are normalized internally (revealing stateless transformation), returns aggregate score, stressed positions, hedges, and plain-language summary. With annotations providing safety info, description compensates well with richer behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.