Cancel Payment Intent

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

The description adds the important behavioral constraint about intent state beyond the destructiveHint annotation. It does not elaborate on side effects like idempotency or webhook triggers, but the core safety constraint is well communicated.

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 with zero redundancy. Every word serves a purpose: the verb, resource, and the critical state constraint.

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 simplicity of the tool and no output schema, the description adequately covers the core purpose and a key limitation. It does not describe return values, but that is acceptable for a cancellation action.

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% for all three parameters, so the baseline is 3. The description does not add additional semantic guidance beyond the schema's own definitions (e.g., pattern, enum).

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 'Cancel' on the resource 'PaymentIntent' and includes a key constraint ('not already succeeded'), distinguishing it from sibling tools like capture_payment_intent or confirm_payment_intent.

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 specifies that cancellation is only possible for intents that are not yet succeeded, which provides a clear precondition. However, it does not mention when to use alternatives (e.g., create_refund for succeeded intents) or explicitly state when not to use the tool.

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