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

Annotations cover read-only/idempotent/open-world safety, and the description goes well beyond them: live read from the company's own site with no third-party database, per-field source attribution, 404 means no charge, and a full payment model ($0.02 USDC via x402 on Base) with the required PAYMENT-SIGNATURE header. That is exactly the kind of operational context annotations cannot express.

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 payload description before commercial details, and every sentence carries information. It is dense and slightly long, with the x402/HTTP-endpoint instructions taking significant space, but none of it is filler.

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 does the heavy lifting by enumerating return fields and source attribution, plus cost and endpoint details. The only gap for a 6-param tool is the unexplained official_checks toggle and the fact that no parameters are strictly required.

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?

With 50% schema coverage, the description compensates by restating the input shape (domain or name, optional city, country, lang en|fr), which clarifies the domain-vs-name intent. It omits the official_checks boolean entirely, leaving one meaningful flag undocumented in both places.

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 opening sentence states a specific verb and resource ('Company profile from a domain or name in ONE call') and enumerates exactly what comes back: industry, services, service area, address, phones/emails with source pages, social links, sanction screening. This is clearly distinguishable from siblings like verify_business or web_search.

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?

It names the intended audience (sales and research agents), scopes the domain ('Businesses only'), and gives concrete failure semantics ('No website found = HTTP 404 = no charge'). It does not, however, explicitly say when to prefer this over verify_business or web_search.

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