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

No annotations are provided, so the description carries the full burden. It usefully discloses the cost model ('5 point per returned record') and enumerates the returned fields, which is real behavioral context. It does not cover auth requirements, what happens on an invalid/unknown CUIT, rate limits, or whether lookups are cached.

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 compact sentences, front-loaded with the identity of the resource and its source, with the returned-field list and pricing trailing. The field enumeration is longish but each item is informative, and nothing is repeated.

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 and no annotations, the description compensates by listing the fields returned (name, company type, contract date, addresses, activities, last update) and the cost. Missing only failure-mode behavior (not found, invalid CUIT), which keeps it short of fully complete for an unannotated 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 the schema already documents the single 'company' parameter with an example CUIT. The description's phrase 'by CUIT or registry link' mirrors that, so it adds no syntax or format detail beyond the structured field; baseline 3 applies.

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?

Names a specific verb and resource ('Get one company from the Argentina registry of legal entities') and identifies the authoritative source (IGJ / Registro Nacional de Sociedades) plus the exact lookup keys. It implies the single-record nature of the call, but never names the sibling run_ar_companies_search, so the differentiation from the search variant is left to inference.

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 input framing ('by CUIT or registry link') implies this is a point lookup rather than a browse/search operation, which is reasonable implied guidance. However there is no explicit when-to-use statement and no mention of run_ar_companies_search as the alternative when the user only has a name rather than an identifier.

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