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

Annotations already declare readOnlyHint=true, non-destructive and closed-world behavior. The description adds valuable operational details beyond that: a 120-month per-call limit, what the response includes (per-month rate or factor, totals, months without data), and that the tool is free. It does not discuss error handling, precision, or behavior when months are missing from totals, but it significantly enriches the behavioral picture.

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?

Purpose is front-loaded in the first clause, followed by the options, the operational limit, the return contents, and a final 'Gratis' note. Every sentence carries useful information, and the description is appropriately dense for a data-conversion tool.

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 must cover return values, and it does ('Devuelve el tipo de cambio o el factor de cada mes, los totales y los meses sin dato'). It also covers limits and cost. It stops short of explaining how months without data affect totals or what the response shape looks like, but it is sufficiently complete for an agent to call the tool correctly.

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%, with detailed enum and format descriptions for every parameter, so the baseline is 3. The description reinforces the rate options and adds the 120-month constraint ('Hasta 120 meses por llamada'), which is not in the schema. Otherwise it largely repeats or summarizes what the schema already documents more precisely.

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 and resource: converts Argentine peso amounts from different months into USD or today's inflation-adjusted pesos. The description names the exact rate sources and adjustment method, and the use cases (billing, salaries, sales) make the scope unmistakable. It is clearly distinct from siblings like inflacion_entre_fechas without needing to name them.

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?

Provides clear usage context through the examples '(facturación, sueldos, ventas)' and the alternative output modes ('dólares... o a pesos de hoy'). However, it does not explicitly say when to prefer this over siblings such as inflacion_entre_fechas, which might also handle inflation-adjusted values. The context is clear but lacks explicit exclusions or routing.

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