Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (readOnlyHint=false, destructiveHint=true, idempotentHint=true), the description adds useful behavioral context: updates are batched, node IDs are prerequisites, and node positions are untouched. The config source note also clarifies where type/config schemas come from.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.