Stream

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states this is a refund operation (implying a financial transaction reversal) but doesn't mention permissions required, whether refunds are reversible, rate limits, or what the response contains. The description adds minimal behavioral context beyond the basic action.

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 extremely concise with just two sentences. The first sentence states the core purpose, and the second provides essential parameter guidance. Every word earns its place with zero wasted text, making it front-loaded and efficient.

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 this is a financial mutation tool with no annotations, 4 parameters at 0% schema coverage, but with an output schema present, the description is minimally adequate. It explains the core action and provides some parameter guidance, but doesn't address behavioral aspects like permissions, reversibility, or error conditions that would be important for a refund operation.

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?

With 0% schema description coverage and 4 parameters, the description provides crucial semantic information for one parameter (refund_reason) by listing its allowed values. However, it doesn't explain payment_id format, refund_note purpose, or the boolean flag's effect. The description adds meaningful value but doesn't fully compensate for the schema coverage gap.

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 action ('Issue a refund') and the target resource ('on a completed payment'), making the purpose immediately understandable. However, it doesn't explicitly differentiate this tool from potential sibling operations like voiding invoices or marking payments as paid, which would require a 5.

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 no guidance on when to use this tool versus alternatives like voiding invoices or marking payments as paid. It mentions the payment must be 'completed' but doesn't explain what constitutes completion or any prerequisites. No explicit when/when-not rules or named alternatives are provided.

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