ack_create_payment_request

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

No annotations are provided, so the description carries the full burden. It discloses the key behavioral trait of combining creation and signing in one step, and mentions the signerJwk can come from ack_generate_keypair, which is helpful. However, it does not describe the output format, potential errors, or side effects, which could be relevant for a tool without annotation support.

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 two concise sentences, each serving a distinct purpose: the first states the core functionality and context, the second contrasts with receipts and points to verification. There is no wasted wording, and it is front-loaded with the most important information.

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 the tool's moderate complexity (5 parameters, no output schema, no annotations), the description provides enough to understand the tool's role and basic behavior. It mentions the 402-use case, the signing step, and the verification tool. However, it lacks details on error conditions or the exact return value, which could be inferred from the schema but are not explicitly stated. Overall, it is sufficient but not exhaustive.

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 coverage is 100%, so parameters are fully documented in the schema. The description adds minimal extra value: it mentions the signerJwk source (ack_generate_keypair) and the verification tool, but does not elaborate on any parameter beyond the schema. With full schema coverage, a baseline of 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?

The description clearly states the tool's verb ('Create'), the resource ('a signed payment request token (JWT)'), and its specific context ('for use in HTTP 402 responses'). It also distinguishes itself from receipts by noting 'Unlike receipts, this creates AND signs in one step', which differentiates it from the sibling ack_create_payment_receipt.

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 gives implicit usage guidance by contrasting with receipts, implying this is for payment requests rather than receipts. It also advises verification with ack_verify_payment_request, which is a clear follow-up step. However, it does not explicitly name the alternative tool or state when not to use this tool, leaving some inference to the agent.

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