Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds no behavioral context beyond what annotations provide—no information about what 'basic information' includes, authentication needs, rate limits, or response format. With annotations covering safety, a baseline 3 is appropriate as the description adds minimal value.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.