Cancelar pagamento Pix agendado do Open Finance

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

The annotation destructiveHint: true already indicates mutation, but the description adds important context: cancellation depends on the payment state ('quando seu estado permitir') and should be done before execution. This goes beyond the annotation's binary flag.

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, directly stating the action and usage guidance. No extraneous words. Front-loaded with the primary function.

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 an output schema and full schema coverage, the description is largely sufficient. It covers purpose and usage timing. It could be more explicit about prerequisites or error scenarios, but for a cancel operation, it is adequately complete.

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 description coverage is 100%, so the baseline is 3. The tool description does not add any extra meaning beyond what the schema already provides for the two parameters. No additional parameter guidance is given.

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 the resource 'pagamento Pix agendado iniciado via Open Finance', identifying the specific transaction type. It distinguishes from similar siblings like of_cancel_recurrency_pix by specifying 'agendado' (scheduled).

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 advises 'Use antes da execução para impedir a movimentação prevista' (use before execution to prevent the planned movement), providing clear timing context. However, it does not explicitly mention alternatives or when not to use this tool, though the condition 'quando seu estado permitir' implies state-dependent applicability.

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