Execute an approved basket using its single-use approval ID, charging the catalog total once per approval.
Execute a basket the gateway approved. Takes only the approval_id; the amount is the catalog total of the approved basket. Each approval works once.
| Name | Required | Description | Default |
|---|---|---|---|
| approval_id | Yes |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only declare idempotentHint=false and destructiveHint=false. The description adds genuinely new behavior: each approval is consumed once (single-use token), and the charged amount is the catalog total rather than caller-supplied, which is important safety context for an irreversible purchase.
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?
Three short sentences, front-loaded with the core action, then the parameter constraint, then the single-use guarantee. No filler or redundancy.
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 one-parameter mutation with no output schema, the description covers the action, the sole input, and the key constraint. It omits failure behavior (expired/consumed approval) and return shape, but these are minor since the output schema is absent and the core semantics are stated.
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 0%, so the description carries the burden and does it well: approval_id is an identifier from a prior approval step, the amount is deliberately not a parameter but derived from the catalog total, and the token is single-use. That is meaning well beyond the bare 'string' type.
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 (execute) and resource (a basket the gateway approved), which is clearly distinguishable from siblings like propose_purchase or get_order. It does not name an alternative sibling explicitly, so differentiation is inferred rather than stated.
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 phrase 'a basket the gateway approved' implies the prerequisite that an approval must already exist, and 'takes only the approval_id' scopes the call. However, it never says when to use this versus propose_purchase or what to do if no approval exists, leaving workflow guidance implicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.