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

With no annotations, the description carries full behavioral burden. It discloses transliteration behavior, error handling (400 on unscreenable names), pricing ($0.01 per call), payment method (x402 in params._meta), and the HTTP endpoint. This is strong, though rate limits or authentication specifics beyond payment are not mentioned.

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 information-dense and front-loaded with the core purpose. Each sentence adds value (sources, inputs, error behavior, pricing, payment, endpoint), though it is slightly long and could be broken into clearer segments.

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 (paid API, multiple list checks, error handling) and no output schema, the description provides most needed context for invocation. It omits return value details, but covers payment, error modes, and input flexibility adequately.

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 baseline is 3. The description adds meaning to the 'names' parameter by indicating it can accept a single name, wallet address, batch, or watchlist—information not present in the schema. The other parameters (days, threshold) are fully covered by the schema and need no further explanation.

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 states a specific verb ('screen') and resource ('sanctions screening') and names the three list sources (US OFAC, UK OFSI, EU). It also mentions acceptable input types (name, wallet address, batch, watchlist), but this overlap with sibling tools (check_sanctions__address, check_sanctions__batch, check_sanctions__watchlist) is not clearly differentiated, so it falls short of a 5.

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 implies usage by listing what you can screen, but it provides no explicit guidance on when to choose this tool over the specialized siblings. There are no exclusions or alternatives named, leaving the agent to infer the correct routing.

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