Cancel payment

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

Annotations already signal destructive and non-read-only behavior; the description adds meaningful context by stating it 'releases any held funds' and restricts applicability to pending/waiting_for_capture states. No contradiction with 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 a single, focused sentence that efficiently communicates the action, scope, and outcome with no redundant information.

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 one-parameter tool with rich annotations and an output schema, the description covers all essential behavioral context: what it does, which payment states are eligible, and the effect of releasing funds. Nothing critical is missing.

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 provided a complete description for payment_id ('ID of the payment to cancel'). The tool description adds no further parameter-level detail, so the schema carries the full burden, warranting a baseline score.

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 uses the specific verb 'Cancel' with the resource 'payment' and explicitly scopes to states 'pending or waiting_for_capture', clearly distinguishing it from sibling tools like capture_payment or create_refund.

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?

Provides clear context by specifying the eligible payment states, implying when this tool should be used. However, it does not explicitly name alternatives for other states (e.g., create_refund for captured payments), so it falls short of full exclusion guidance.

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