Cancel transaction

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

The description explicitly labels the operation as a destructive write, consistent with annotations, and adds real consequences: it may prevent or reverse payment processing and requires confirmation. This is useful behavioral context beyond the 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?

Two compact sentences front-load the destructive nature and clearly state the core action, consequence, and caution with no wasted words.

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 simple two-parameter destructive tool, the description covers the essential semantics and risk, but leaves gaps: no state prerequisites, no explanation of idempotencyKey, and no indication of what the response contains given there is no output schema.

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 description adds no parameter-level meaning; with 0% schema description coverage, id and idempotencyKey rely on their names alone. The id is loosely implied as the transaction to cancel, but idempotencyKey's purpose is entirely unexplained.

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 states a specific action ('cancel a ZEN transaction') and identifies the resource, so an agent knows what the tool does. It does not differentiate cancellation from the sibling refund_transaction or capture_transaction, which keeps it from 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 only usage guidance is a caution to 'confirm before use,' which does not say when cancellation is appropriate versus alternatives like refund_transaction. There is no mention of transaction state or conditions that select this tool.

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