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 that the tool is paid, requires a two-step x402 payment flow, and that the first call returns payment terms rather than data. This is important behavioral context, though it doesn't cover error handling or response format.

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 three sentences, each earning its place: purpose, payment flow, and pricing tool reference. It is concise and front-loaded with the core purpose.

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 and no annotations, the description should explain return values. It covers payment mechanics and matching modes well, but does not describe the response format, pagination, or behavior when no match is found. It is adequate but has gaps.

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 baseline is 3. The description restates matching criteria (fuzzy name, exact call sign, IMO, flag) and the x_payment flow, but the schema already documents each parameter, including x_payment's detailed explanation. The description adds minimal new parameter-level information.

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 screens vessels against OFAC maritime designations using multiple identifiers (fuzzy name, exact call sign, IMO) and flag filtering. This distinguishes it from sibling tools like sanctions_screen or sanctions_entity.

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 explicitly explains the paid flow: call without x_payment to get terms, sign them, and call again with x_payment. It also points to the `pricing` tool for listing all prices. However, it doesn't explicitly contrast with non-vessel sanctions screens.

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