Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are largely covered structurally. The description adds that the search spans multiple legal source types (statutes, precedents, interpretations, tribunal decisions), which is genuinely useful behavioral context. It says nothing about result limits, ranking, or response shape, so with annotations carrying the safety profile 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.