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

Beyond the annotations (destructiveHint=false, idempotentHint=true), the description discloses that the row is deactivated rather than deleted and that historical events remain accessible via recent_alerts. This adds meaningful behavioral context about side effects and data persistence.

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, each carrying essential information: the primary action in the first sentence, and key behavioral details in the second. 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 one-parameter tool, the description covers the action, ownership constraint, side effect (deactivation), and data persistence. Combined with clear schema and annotations, it fully equips an agent to use the tool correctly.

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 already fully describes the 'id' parameter with type and provenance ('Subscription id (uuid) returned by subscribe'). The description only restates that canceling happens by id, adding no new semantic detail. Baseline 3 is appropriate given 100% schema coverage.

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 opens with a specific action and target: 'Cancel a subscription by id.' This clearly distinguishes it from sibling tools like subscribe and list_subscriptions. The verb 'cancel' and resource 'subscription' are 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?

The description provides clear context on usage, including ownership restrictions ('you can only cancel your own subscriptions') and the deactivation behavior. It does not explicitly name alternatives or when not to use, but the context is sufficient for a single-purpose tool.

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