Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure. 'Cancel a meal registration' implies a destructive mutation, but the description doesn't specify whether this requires specific permissions, whether cancellations are reversible, what happens to associated billing, or any rate limits/quotas. For a mutation tool with zero annotation coverage, this is inadequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.