Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds only the HTTP verb/path (GET /api/system/health), which slightly corroborates the read-only nature but discloses nothing about auth requirements, rate limits, or what 'health' actually reports.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.