Huỷ phiên thanh toán

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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered structurally. The description adds useful non-obvious behavior beyond that: the state machine constraint that only pending checkouts are cancellable and paid/expired/cancelled ones are terminal.

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 tight sentences (bilingual) with the core action and the key state constraint front-loaded; nothing extraneous. Every clause earns its place.

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 2-parameter mutation with full schema coverage, rich annotations, and no output schema, the description supplies the state preconditions an agent needs to avoid a failing call. It could note side effects (e.g., what happens to a held amount) but is otherwise complete enough.

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%, so checkout_id and idempotency_key are already documented in the schema (including the auto-UUID fallback for idempotency_key). The description adds nothing about parameter format or constraints, so the baseline 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?

States a specific verb+resource combination ('Cancel a pending checkout') and constrains it to the pending state, which makes the intent unmistakable. It does not explicitly name a sibling tool (e.g., cancel_qr or get_checkout) to differentiate, so a 4 rather than 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?

Gives a clear state-based precondition for use ('pending') and an explicit when-not ('paid, expired hoặc cancelled không thể huỷ lại'), which is genuinely actionable guidance. It stops short of naming alternative tools for those other states, so it falls just below a 5.

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