Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds a modest behavioral hint that the record is 'stored public' (cached dataset rather than live lookup), but says nothing about return shape or miss/error behavior. With annotations carrying the safety burden, a 3 is appropriate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.