Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose the destructive nature via the verb 'Delete', the operational scope ('single... by ID'), and the authorization prerequisite ('Requires Write on CustomProperty'), which is genuinely useful context. It remains silent on failure behavior for non-existent IDs, whether deletion cascades to property values attached to devices or groups, and what a successful response looks like.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.