PayeeProof

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

The description adds substantial behavior beyond the annotations: the paid $0.01 nature, never authorizing the target payment, never forwarding credentials, probing only anonymous GET/HEAD under an SSRF-safe contract, and the open-world caveat that missing evidence can remain unknown. These details materially affect how an agent should invoke and interpret the tool.

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?

Four dense sentences, each earning its place: purpose, usage timing, safety behavior, and scope exclusions. Information is front-loaded and nothing is repeated from the schema.

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 complexity (13 parameters, nested input object, output schema), the description covers what an agent needs to select and call it: when to use it, what it checks, what it will and will not do, and what limitations apply. The existing output schema relieves the description of explaining return values.

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 the schema already documents each parameter. The description adds a high-level consistency-checking framing but no per-parameter detail beyond what the schema provides, putting it at the baseline score of 3.

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 names the exact object of assessment (public machine identity and payment-destination consistency) and the action ('compare') in the second sentence, making the tool's purpose unmistakable. It also disambiguates the tool from adjacent services like KYC, AML, and legal verification, so an agent cannot confuse its scope.

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 explicitly tells the agent when to use it ('immediately before an autonomous machine payment') and gives a conditional behavioral rule for state-changing target methods versus active probing. The closing exclusion list covers when-not-to-use cases, even though no sibling tools are listed.

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