Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare a non-readonly, non-destructive, non-idempotent write, but they cannot express the side effect the description supplies: a presentation already in another project is moved out of it. That cross-resource mutation is exactly the kind of context annotations miss, though permissions/limits are not mentioned.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.