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

With no annotations, the description carries the full burden and does reasonably well: it discloses the return fields (list, programme, reference, match_score, matched_alias), the pricing/access model (0.03 USD per call via x402), and an explicit accuracy disclaimer. It omits what happens with no matches (empty result vs error) and any rate limits, hence not a 5.

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 dense sentences, front-loaded with the capability and list coverage, then return shape, then the disclaimer and price. Nothing is redundant with the title or padding.

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 3-parameter read tool with no output schema, the description covers scope, return fields, pricing and a disclaimer well. The remaining gap is the unexplained `type` parameter and the lack of routing against the eu_sanctions sibling.

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 the required `name` and the `lists` subset codes (eu, ofac, uk, un), which the description merely echoes. The description adds no clarification for the opaque `type` parameter, whose schema description is literally 'type', leaving a real gap that baseline-3 scoring reflects.

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 the specific verb 'Screen' plus the resources covered (person, company, vessel name) and enumerates all four sanctions lists screened simultaneously. An agent can distinguish it from the sibling eu_sanctions tool because the description makes clear this is a multi-list aggregation rather than an EU-only check.

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 carries a caveat ('Screening aid only; human review required') that implies a compliance-adjacent use case, but it never states when to call this versus the sibling eu_sanctions tool or when not to (e.g. name already screened). Usage is inferable from the list enumeration rather than explicitly guided.

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