Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false), and the description adds genuinely new behavioral facts: the result is an immutable historical snapshot rather than a recomputation, and access is scoped to "the key that created it and to its enterprise workspace." It omits rate limits or pagination behavior, but those are secondary here.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.