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

Goes well beyond the annotations: discloses that VAT IDs are checked live in EU VIES, that LEI matching only occurs on an exact name match, that JS-rendered sites are handled, that natural-person names are deliberately excluded, and that no charge applies when no imprint is found. The x402 payment mechanics and price are also spelled out, which is essential behavior for a paid call.

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?

Front-loaded with the core purpose and return fields before moving to use cases and payment logistics. It is long, but nearly every sentence carries information an agent needs (data source, exclusions, pricing, free-sample path); only the domain example is mildly redundant with 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, the description compensates by enumerating the returned fields (legal name, legal form, address, phone, email, register numbers, VAT ID, LEI). Payment, error/charging behavior and coverage limits are all covered, leaving nothing an agent needs before invoking it.

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 parameter is fully documented in the schema, so the description's 'Send domain, e.g. zalando.de' largely restates it. The example JSON input adds a little usage clarity but no format or validation detail beyond the schema, matching the baseline for high-coverage schemas.

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 (enrichment) and resource (company from a domain) with a clear geographic scope (DE, AT, CH) and a concrete data source (the Impressum). It enumerates exactly what is returned, which cleanly separates it from siblings like company_lookup, company_brief and kyb_check.

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 explicit use cases (lead enrichment, CRM cleanup, supplier onboarding, KYB), a concrete invocation example, and an input format hint ('Send domain, e.g. zalando.de'). It does not, however, name or exclude the closest siblings (company_lookup, company_brief) or state when a different tool is preferable.

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