Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already provide readOnlyHint=true, destructiveHint=false, and idempotentHint=true, which cover safety and idempotency. The description adds modest behavioral context by listing return fields ('signal score, last fired timestamp, total alerts fired, and subscription configuration'), but these are also documented in the output schema. No contradictions with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences with no wasted words. It front-loads the purpose and then lists return fields and usage guidance. Every sentence adds value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the simple input schema, presence of output schema, and comprehensive annotations, the description covers the essential use case. It mentions usage after subscribe and key return fields. Minor gaps: it does not explicitly mention that the subscription must exist or error behavior, but the agent can infer from the operation type. Overall, sufficient for correct selection and invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the parameter 'subscriptionId' already has a clear description in the schema ('UUID returned by intelligence.subscribe'). The tool description does not add additional semantic meaning beyond what the schema provides, so a baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Check the status') and resource ('intelligence subscription by ID'), explicitly lists the returned fields (signal score, last fired timestamp, etc.), and distinguishes itself from sibling tools by mentioning its relationship to 'intelligence.subscribe' and implicitly differentiating from 'intelligence.subscription.delete'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states when to use this tool: 'Use after intelligence.subscribe to verify a subscription is active.' This provides clear usage context. However, it does not explicitly state when not to use it or mention alternative tools for other scenarios (e.g., listing all subscriptions), though the sibling set makes the purpose clear enough.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.