Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds rationale (prevent injection) but does not disclose deeper behavioral details like which characters are encoded, UTF-8 handling, or edge cases, though the mode parameter hints at encodeURI behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.