Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate the tool is read-only, open world, and idempotent. The description adds behavioral context by listing the specific data fields returned (mastery level, points, chest granted, tokens earned), which is beyond what annotations provide. No contradictions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.