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

The description adds context beyond annotations: it explains the auth requirement (ownership) and the soft-delete behavior (deactivation). Annotations already indicate non-destructiveness (destructiveHint: false), and the description reinforces this consistently.

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?

Two sentences, front-loaded with the core action, followed by key constraints and effects. No unnecessary words; every sentence earns its place.

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?

For a single-parameter mutation tool with full schema coverage, the description is complete. It covers purpose, ownership constraint, and behavioral nuance, and references relevant sibling tools.

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% — the param 'id' is fully described in the schema. The description does not add additional parameter semantics beyond what the schema provides, so baseline score of 3 applies.

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 clearly states 'Cancel a subscription by id,' specifying the verb and resource. It contrasts with sibling tools like 'subscribe' and 'recent_alerts,' making the tool's purpose unambiguous.

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?

Explicitly notes ownership enforcement ('you can only cancel your own subscriptions') and the non-destructive nature ('row is deactivated, not deleted'), providing clear when-to-use and when-not-to-use context. References 'recent_alerts' for historical data access.

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