Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: what a template conceptually is, that it renders from a small controls object, and how it relates to the render tools. It does not discuss return shape, but an output schema exists so that burden is not on the description.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.