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

Annotations already cover readOnly, idempotent, openWorld and non-destructive, so the safety profile is settled. The description goes beyond them by disclosing a rate limit ('a few free samples a day') and a per-call price with a payment mechanism (x402), which materially affects whether and how often an agent should call it.

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 with no filler, and the substantive content leads. The first sentence is a verbless fragment, which slightly hurts readability, but nothing is wasted.

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 an output schema present, the description need not enumerate return fields — yet it spends its entire first sentence doing exactly that while omitting the core statement of the action. Annotations and schema carry the rest, so it is adequate but leaves the agent without usage routing.

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 all six parameters including the list codes, threshold range and corroboration fields. The description only echoes some of these concepts ('score', 'countries', 'dates of birth') as output fields and adds the fact that all lists are searched by default, which is a marginal increment.

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 is a noun phrase about results ('Potential matches across all four lists with score, list, programmes...') rather than a verb+resource statement of what the tool does; the action must be inferred from the title. 'All four lists' weakly distinguishes it from sanctions__screen-uk and sanctions__screen-us, but that contrast is never made explicit.

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?

There is no when-to-use guidance at all. The only second sentence concerns pricing ('A few free samples a day, then $0.02 USDC per call via x402'), which is cost information, not routing advice, and the description never says why an agent should pick this over the sibling sanctions__screen-uk or sanctions__screen-us.

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