Obtener CUIT a partir de DNI

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered, but the description adds nothing beyond the bare purpose: no mention of whether the lookup hits an external registry, what happens on a miss, or whether the result can be cached/trusted. For an open-world lookup this leaves behavioral gaps.

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?

A single front-loaded sentence with zero waste. It is appropriately sized for a one-parameter lookup, though it is so terse that it leaves obvious questions unanswered rather than being an example of tight, complete phrasing.

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?

The tool is simple (1 param, no nesting) and annotations cover safety, but there is no output schema, so the description should say what the returned CUIT looks like (format, whether null on miss). That missing return-shape/edge-case context keeps it at minimum viable.

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 the single nationalId parameter is documented as 'DNI del contribuyente', which matches the description's phrasing. The description adds no format constraints (digits only, with/without dots, length), so baseline 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?

States a specific verb (obtiene) and resource (CUIT del contribuyente) with the input (DNI), so an agent immediately knows the transformation performed. It does not distinguish itself from the related sibling get_taxpayer_details, which also deals with taxpayer data, so it stops short of a 5.

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 guidance on when to use this instead of get_taxpayer_details or other taxpayer lookups, and no mention of failure conditions (e.g., DNI not found, invalid DNI). The agent must infer usage from the name alone.

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