cancel_payment_token

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

No annotations are provided, so the description carries full weight. It discloses that the tool cancels a token and refunds instantly, and implies freeing a card slot. However, it omits important behavioral details such as irreversibility, prerequisites (e.g., token must be unused), or failure modes (e.g., token already used).

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 terse sentences, with the primary action front-loaded. Every word earns its place; no filler or redundancy. It efficiently combines purpose and usage guidance in minimal space.

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 tool's moderate complexity (2 required params, no output schema), the description covers purpose, usage, and one behavioral side effect (refund and freeing a card slot). It stops short of a 5 by not mentioning reversibility or potential errors, but overall it provides sufficient context for an agent to invoke the tool correctly in most scenarios.

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%: both token and reason parameters have descriptions. The tool description does not add extra meaning about parameter formats or constraints beyond the schema. It slightly implies the token should be unused, but that is a condition, not a parameter clarification, so the baseline 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 opens with a clear verb+resource combination: 'Cancel unused token and refund instantly.' This explicitly states the tool's primary action and object, distinguishing it from siblings like request_payment_token (creates tokens) and execute_payment (uses tokens). The name aligns perfectly with the described functionality.

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 explicit contexts for use: 'Use when user cancels the purchase or to free up a card slot.' This gives clear situational guidance. However, it does not mention when not to use the tool or suggest alternatives, so it falls just short of a 5.

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