expire_checkout_sessionExpire an open checkout session to prevent further payment through it. Returns 409 if the session is already complete or expired.
Expire an open checkout session.
Expire an open checkout session so the customer can no longer pay through it. A session that is already complete or expired returns 409.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | The checkout session id (`cs_…`). |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and idempotentHint=false. The description adds real value beyond them: the business effect (customer can no longer pay) and the error semantics (409 when the session is already complete or expired), which tells the agent how to handle a repeat call or a stale id. It does not say what is returned on success, but annotations carry the safety profile.
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 short sentences, front-loaded with the action and immediately followed by the effect and the 409 edge case. The opening sentence merely restates the title and tool name, which is the only wasted line.
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 single-parameter mutation tool with no output schema, the description covers effect, precondition and error case, and annotations cover the safety profile. The remaining gap is the success response shape, which is minor but non-trivial for an agent needing to confirm the expire succeeded.
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% and the only parameter 'id' is documented in-schema as the checkout session id with the `cs_…` prefix. The description adds no further meaning about the id, so the schema does all the work and baseline 3 applies.
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 verb ('Expire') and resource ('an open checkout session'), which cleanly separates it from the many read/create checkout-session siblings such as get_checkout_session, list_checkout_sessions and create_checkout_session. No other sibling performs this operation, so an agent can route to it without opening the schema.
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?
It gives the operative context — 'so the customer can no longer pay through it' — and an implicit precondition that the session must still be open, since already-complete or expired sessions return 409. It does not explicitly contrast with alternatives (e.g. leaving a session to naturally expire), so it stops short of full when/when-not guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.