Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It states the core mutation but does not mention required authentication, overwrite behavior, error cases for missing or invalid ids, or whether the update is reversible. This leaves important behavioral context unstated.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.