Cancelar uma assinatura

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

Annotations already indicate destructive and idempotent behavior. The description adds that it stops future billing and only applies to active subscriptions, but doesn't detail side effects like refunds, pending charges, or irreversibility. It does not contradict 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 long, directly states purpose and usage context, and contains no extraneous content.

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 presence of annotations, output schema, and simple parameter set, the description covers the essential aspects: what it does and when to use it. It could mention that the subscription must be active and the result is idempotent, but these are implied or covered by annotations.

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%, with the parameter 'id' already described. The tool description adds no additional information about parameters, so baseline score 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 clearly states the verb (cancela) and resource (assinatura ativa) and the specific effect (interrompe cobranças futuras). It distinguishes itself from sibling cancellation tools like cancel_charge and cancel_carnet by targeting subscriptions.

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 a clear use case: 'Use quando o cliente não deve mais permanecer vinculado à recorrência do plano.' It does not explicitly state when not to use it or mention alternatives, but the context is sufficient for an agent to decide.

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