Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already disclose readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the agent knows this is not a safe read-only operation. The description adds 'Returns SVG', which clarifies the output format, but does not disclose other behavioral traits such as permissions, side effects, or rate limits. Given annotations exist, this is adequate but not exceptional.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.