Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is fully specified. The description adds value by naming 'public MCP' and 'local vigisky-sentinel', indicating scope (public vs local) and transport (stdio/127.0.0.1). This is beyond what annotations provide, earning a 4.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.