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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds context those annotations cannot: the exact cost (0.005 USDC via x402 or 3 credits), the first-5-calls-free allowance, and the crucial semantic point that these lists restrict trade rather than freeze assets. That is exactly the value-add the description should supply.

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 usage instruction and the list scope are front-loaded, and the payment details are compressed into two short sentences with no filler. It is dense but every sentence carries operational information; only the phrase about the sanctions screen is slightly indirect.

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?

There is no output schema, so the description should explain what a screening call returns (hit/no-hit, matched list, score vs. threshold) — it does not. Combined with the phantom 'threshold' parameter, the definition leaves an agent unsure how to interpret results even though cost and list scope are well covered.

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 description says 'Input: name, optional type (entity or person), threshold' — but the schema has no threshold parameter at all, which will mislead an agent into supplying a non-existent argument. The type enum is present in the schema but left unexplained in both description and schema, and the meaning of a match score is never clarified.

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 a specific verb+resource: screens a name against the US Consolidated Screening List and the DHS UFLPA Entity List, naming the contributing agencies (Commerce, State, Treasury). It also carves itself out from the sanctions sibling by declaring the SDN list is excluded and noting these are trade restrictions, not asset freezes — an agent can distinguish it from eu_sanctions_screen and pep_screen without opening schemas.

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?

Gives a clear triggering context: 'Use before buying from, selling to or shipping to a company, above all a Chinese or Russian one.' It also implicitly routes SDN-list checks to the sanctions screen. It stops short of naming that sibling tool or stating explicit exclusions (e.g. individuals vs. entities, non-US jurisdictions).

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