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

The description discloses the full calculation behavior: index-based adjustment over the contract, correction of each overdue month through today, 1% monthly mora interest, late-payment penalty, and monthly-plus-total output. This goes well beyond the readOnlyHint/idempotentHint annotations and is consistent with them, with no contradiction.

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 dense sentence front-loads the use case and legal basis, then describes the calculation steps in order, and ends with the return shape. No filler or repetition; every clause adds information.

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 description is adequate to identify the tool and understand its main behavior, but for a complex legal-financial calculation with 9 parameters, no output schema, and no per-property descriptions, it leaves notable gaps: no default assumptions when optional parameters are omitted, no date format guidance, and only a vague 'detalhamento por mês + total' for return structure.

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 0%, so the description must compensate. It adds meaning to core parameters: aluguel_inicial, inicio_contrato, inicio_atraso/fim_atraso, juros (1% a.m.), multa, and indice are all referenced directly. However, it does not explain optional parameter semantics such as periodicidade_meses, whether juros/multa are overrides or defaults, or expected date formats, leaving gaps for a 9-parameter tool.

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?

The description names a specific resource ('Aluguéis em atraso (Lei 8.245/91)') and a clear set of actions: it adjusts the rent by the index, corrects each overdue month until today, applies 1% monthly mora interest and a late-payment penalty, and returns a monthly breakdown plus total. This clearly distinguishes it from sibling tools like calculo_indice or calculo_atualizar.

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 opening phrase 'Aluguéis em atraso' clearly signals the intended scenario: overdue rent calculations under Brazil's Lease Law. It does not explicitly name alternatives or state when not to use it, so it falls short of full routing guidance, but the context is unambiguous enough for an agent to select it over related calculo_* tools.

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