Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare the mutation profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), so the safety burden is light. The description adds real behavioral context beyond that: the source text is cloned as an initial draft, the result is returned immediately, and codes must stay identical to the source. It stops short of describing failure modes or partial-state behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.