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

Annotations already declare openWorldHint=true, idempotentHint=true and destructiveHint=false, so the description's job is to add cost and side-effect context — and it does: 'Uses one lookup credit when the details are not already stored' explains both the billing impact and the caching/storage behavior that justifies readOnlyHint=false. It stops short of stating what happens on a miss or a failed lookup.

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?

Two sentences, front-loaded with the capability and field list, followed by the cost caveat. No filler and nothing repeated from the title.

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?

An output schema exists so return values need not be described, and annotations cover the safety profile. The credit note closes the main behavioral gap; what remains unstated is the zero-required-parameter edge case and whether either input is preferred, which is a modest omission for an enrichment tool.

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 description coverage is 100% and both parameters are documented in the schema, so the baseline is 3. The phrase 'from its own domain or its public page link' mirrors the two params and signals they are alternatives, but adds no format, precedence, or fallback semantics beyond what the schema already says.

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 ('find') plus resource ('company's details') with an enumerated field list (industry, size, location, website, phone, technologies) and the two accepted input sources. It implicitly separates itself from search_companies and find_contact_details by being a detail-enrichment lookup rather than a search or person lookup, though no sibling is named outright.

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?

No statement of when to prefer this over search_companies or find_contact_details, and no guidance on choosing between domain and profile_url or what happens when neither is supplied (required parameters = 0). The only decision-relevant note is the credit cost, which is billing behavior rather than usage routing.

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