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

Beyond the readOnlyHint/openWorldHint annotations, it discloses two non-obvious behaviors: results are ordered so paid Pro members appear first with paid_placement=true, and that a no-result search still returns an actionable RFQ link. The paid-placement disclosure is exactly the kind of ranking bias an agent should know about; more detail on result limits or pagination is the only gap.

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 tight sentences: purpose first, then the empty-result fallback, then the ranking caveat. Every sentence carries information an agent needs and nothing is repeated from the schema.

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 only one parameter, the description carries the burden of explaining returns, and it does so for the key fields (RFQ link, paid_placement flag). It remains silent on result volume, pagination, or whether queries are logged, which are minor omissions for this tool type.

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 coverage is 100% and the single 'product' parameter is fully documented in the schema with an example. The description's 'by product' matches the schema without adding syntax or format guidance, so the baseline 3 applies.

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?

Specific verb+resource+filter: 'Search the Fromerica directory of U.S. manufacturers and exporters by product.' It names the platform, the entity type, and the search dimension, which clearly separates it from siblings like get_us_export_markets or find_schedule_b that deal with aggregate trade data rather than supplier lookup.

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 frames the use case (a buyer/importer looking for suppliers of a product) and explains the fallback path when nothing is listed: an RFQ link shown to matching suppliers. It does not name alternatives explicitly, but the sibling set is functionally distinct enough that the context is unambiguous.

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