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

Beyond the annotations, the description discloses important behavior: ownership restriction and that the row is deactivated (not deleted), preserving historical events. This adds meaningful context not covered by annotations, with no contradictions.

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 action, and every sentence provides value. No filler or redundancy.

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 simple tool with one parameter, no output schema, and useful annotations, the description covers the key aspects: what it does, ownership constraints, side effects (deactivation), and how to keep history. No major gaps.

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?

The schema fully covers the single parameter 'id' (description: 'Subscription id (uuid) returned by subscribe'). The description merely says 'by id,' adding no extra semantics. With 100% schema coverage, a baseline 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 the tool's purpose: 'Cancel a subscription by id.' It uses a specific verb ('cancel') and resource ('subscription'), and the title 'Unsubscribe from Alerts' reinforces this. It distinguishes from sibling tools like subscribe (create) and list_subscriptions (list).

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 provides explicit when-to-use and when-not-to-use guidance: ownership is enforced, so you can only cancel your own subscriptions. It also points to an alternative for historical events via recent_alerts, making the intended use clear.

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