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

No annotations, so description carries full burden. Discloses pricing ($0.10 per call via x402), sources (live from homepage/legal pages, VIES), and what it confirms (real EU business). Could add limitations like non-EU domains, but still strong.

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?

Detailed single paragraph, but front-loads pricing and USDC mention which may not be primary. Could be more structured with bullet points. Adequate but not exemplary.

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 one parameter, no output schema, and no annotations, the description covers inputs, outputs, target audience, pricing, and unique value. Fully adequate for agent to use correctly.

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% with one parameter 'domain'. Description adds context by specifying domain should be for EU/NL targets and explains what the tool returns, adding value beyond schema.

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?

Clearly states it enriches companies from domain, specifying EU/NL focus and listing detailed outputs. Distinguishes itself from generic enrichers by mentioning VIES validation and KvK/BTW numbers.

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?

Explicitly states ideal use case: qualifying EU/NL leads. Mentions pay-per-call pricing. Does not explicitly contrast with siblings or state when not to use, but context is clear.

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