Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, and non-destructive behavior, so the bar for additional behavioral context is lower. The description adds useful operational detail by explaining the draft/version behavior and instructing agents to follow any llmContext guidance in results.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.