Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine context by disclosing upsert semantics ('Creates or replaces'), which the annotations do not convey, but it says nothing about what happens to an existing alias beyond replacement, permission requirements, or error behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.