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

With no annotations, the description does carry useful behavioral facts: a hard cap of 10 results per request and that auth/charges flow through the caller's gateway credentials. However, it does not say what each result contains (domains? names? IDs?) or whether matching is prefix vs substring, which matters for an autocomplete endpoint with no output schema.

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?

Roughly three short sentences with no filler, and the core behavior leads. Minor flaws: the first two sentences are run together without punctuation, and the credentials/billing sentence is secondary yet placed prominently.

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 one-parameter, no-output-schema lookup tool, the description covers result count and auth context, which is most of what an agent needs to invoke it. The remaining gap is the shape of returned items, which is the one thing that would let an agent chain this into an enrich call without guessing.

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% for the single query parameter, so the schema already documents it; the description adds only the 'partial' qualifier. It actually narrows the schema's 'partial domain or company name' to 'partial domain name', which mildly under-describes accepted input rather than enriching it.

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 concrete verb and resource: returns a list of companies matching a partial query, capped at 10. It is clear enough to distinguish from enrich/get siblings in the abstract, but it never names or contrasts those siblings explicitly, and it describes the input as a 'partial domain name' while the title frames the goal as resolving a company name to a domain.

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?

There is no when-to-use guidance: nothing tells the agent this is the cheap lookup step to run before treg_get_call_companyenrich_companies_enrich or _get, and no exclusions are given. The only contextual note is about gateway credentials and billing, which is not usage guidance.

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