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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false. The description adds valuable behavioral traits beyond annotations: 'Keyless, no login' (authentication model), 'live' lists (real-time nature), 'match score' (result granularity), and pricing ($0.01/call, x402 USDC). It does not contradict annotations and enriches the agent's understanding of side effects and constraints.

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: first sentence for core action, second for access and purpose, third for pricing. It is front-loaded with the primary verb and resource, uses no filler, and is immediately scannable. Perfectly sized for the tool's simplicity.

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?

The tool has no output schema, so the description should compensate by outlining the return format. It mentions 'flags potential hits with a match score' but does not specify the structure (e.g., list of matched names, scores, match details). For a screening tool, an agent would benefit from knowing what to expect in the response. Given the moderate complexity and well-covered parameters, the description is adequate but not fully complete.

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?

The input schema has 100% description coverage, with each parameter (names, minScore, maxConcurrency) already well-documented. The description adds high-level context ('live lists,' 'match score') but does not provide additional parameter-specific details beyond what the schema offers. The baseline of 3 is appropriate, as the description adds marginal value to parameter semantics.

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 action ('Screen names'), the resource ('live OFAC SDN and EU consolidated sanctions lists'), and the outcome ('flags potential hits with a match score'). It distinguishes itself from sibling tools like 'sanctions-update-alert' and 'litigation-check' by focusing on live screening for onboarding, making its purpose unambiguous.

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 mentions a use case: 'before onboarding a client or counterparty,' which guides when to use the tool. However, it does not explicitly state when not to use it or point to alternatives (e.g., 'sanctions-update-alert' for updates). The context is clear enough for an agent to infer appropriate usage, but lacks direct exclusion cues.

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