Check an agent before paying it (free)

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description adds real context instead: it is free, it returns 'facts' rather than a verdict ('the decision stays with you'), and it discloses sampling limits (payments taken from the 25 newest, statement staleness). The refuse-condition framing is useful behavioral disclosure.

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 purpose clause is front-loaded, but the middle is a single run-on chain of comma-linked returns that is hard to parse. The trailing upsell sentence is relevant but adds length; the content earns most of its space yet the structure could be tightened.

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?

With no output schema, the description must carry the return contract, and it does enumerate the returned fields and the sampling caveat. Only minor gaps remain, such as the exact shape of 'flags' or the enumerated refuse conditions, which are referenced but not listed.

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% and the single 'agent' parameter is described there as 'Agent token id, slug or bound wallet.' The description adds no extra meaning about the identifier format, so the baseline of 3 for high schema coverage 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 opening states a specific verb, resource and scope: 'One free call before your agent pays or hires another,' and it enumerates exactly what facts come back (statement, incidents, 72h detections, approvals, last payment). It implicitly separates itself from agent_statement and detections by being an aggregate pre-payment check, though it never names those siblings directly.

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 a clear triggering condition ('before your agent pays or hires another') and points to the paid precheck pack as the richer alternative for the counterparty address. It stops short of explicit when-not-to-use guidance (e.g. after payment, or when a full statement is needed).

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