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 mentions only what fields are updated and what is excluded, but does not state whether updates are partial or full replacement, side effects, authentication requirements, or the implication of the agent parameter for acting on behalf of others.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.