Look up the company behind a domain

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

Annotations already provide readOnlyHint and openWorldHint, so the description does not need to re-state safety. It adds useful behavioral context beyond annotations, including the one-credit cost and the specific firmographic fields returned, which are not present in the schema or annotations.

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?

The description is three short, purposeful sentences with no filler. It front-loads the core behavior and output, then states the use case and cost, all in under 40 words.

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?

For a low-complexity, single-parameter, read-only lookup, the description is complete: it explains input, output fields, when to use it, and cost. The schema fully covers the parameter format, and the annotations cover safety, so no critical information is missing.

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 the single 'domain' parameter already documented as a bare domain with no scheme or path. The description adds no additional parameter semantics beyond what the schema provides, so the baseline score of 3 is appropriate.

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 description clearly states a specific verb-resource pair: given a domain, return the company behind it. It lists the exact output fields (name, industry, city, country, address, LinkedIn URL), making its purpose unmistakable and distinguishing it from domain-technology and technology lookups.

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 explicitly says when to use it: when asked who owns or operates a website, or to enrich a domain into firmographics. It does not explicitly name alternatives or exclusions, but the stated use cases are clear enough for an agent to select this tool.

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