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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely useful context they cannot convey: per-request credit consumption, that failed requests also consume credits, and the required API key.

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-loads the returned data, then tacks on plan/credit/auth notes in a compact set of clauses. Every sentence carries information; only slight compression could improve it.

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 compensates by listing the fields returned, and it covers auth and billing. It is nearly complete for a single-purpose, two-parameter enrichment call, though it does not detail the shape of range-type fields.

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%, so the schema already documents 'domain' and 'fields' fully, including URL normalization and the key-list pattern. The description's field enumeration loosely corresponds to the 'fields' filter but adds no syntax or format detail beyond the 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?

States a specific verb+resource ('Firmographic data for a company web domain') and enumerates the returned data categories, making it instantly distinguishable from the validation, lookup, currency and holiday siblings. An agent knows exactly what this yields without opening the schema.

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?

Gives clear operational context — it is the Company Enrichment API, costs 1 credit per request (including failures), and requires the Company Enrichment API key. However, it never names an alternative or states when-not to use it relative to other abstractapi tools.

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