Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds meaningful content context (bonuses are tied to a qualifying purchase) but discloses nothing further about behavior such as pagination, freshness, or market-specific availability.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.