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

Annotations already cover readOnly/openWorld/idempotent/non-destructive, and the description adds genuinely new behavior: zero credit cost, works without a PeopleSearch.im account, and hard limits of 3 companies and 10 searches/day in that unauthenticated state. It does not say whether authenticated results are capped or how pagination works, which keeps it below 5.

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 purpose and return fields, then the query modes, then cost and limits — a logical order with no filler sentences. The description is on the longer side for a single-parameter tool, but each clause (cost, limits, three modes) carries information an agent needs.

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?

No output schema exists, so the description correctly names the return fields and the result limits itself. Combined with annotations covering the safety profile, an agent has everything needed to decide to call it and interpret the response.

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% and there is only one parameter, so the baseline would be 3, but the description adds real meaning beyond the schema by giving concrete examples of each accepted query form ('warmly.ai', 'Warmly', 'Series B fintech companies in London with 50-200 employees') and the differing result cardinality of each.

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 ('Search a global company database') and enumerates the returned fields (industry, size, location, website). It clearly differentiates itself from lookups by describing three input modes and the fan-out behavior of each (website returns one company; name/description can return many).

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 explicit guidance on how to phrase the query and what each phrasing yields, plus a cost condition ('FREE and spends no credits') and a pre-account fallback path. It stops short of naming siblings (lookup_company, find_company_emails) that an agent might otherwise confuse it with, so it lacks explicit alternative routing.

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