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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral detail: it reajusta by index, corrects each late month, applies 1% monthly interest and late penalty, and returns a month-by-month breakdown plus total. This is substantive beyond the annotations.

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?

The description is compact: three sentences, front-loaded with the core purpose, then quick detail on the calculation logic and output. Every sentence adds value and there is no filler.

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?

For a legal calculation with 9 parameters and no output schema, the description is not complete. It gives the high-level formula and a minimal output summary, but omits parameter roles, date formats, optional-field behavior, and details of the returned monthly breakdown. An agent would likely need to inspect schemas or examples to call it reliably.

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 for 9 undocumented parameters. It only alludes to 'índice', 'juros', and 'multa', but does not explain the required date fields, aluguel_inicial, data_calculo, or periodicidade_meses. It also states a fixed 1% monthly interest and penalty while the schema exposes juros and multa as parameters, which may confuse agents about whether those are overrides.

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 states a specific verb and resource: it calculates overdue rent adjustments under Lei 8.245/91, covering index-based adjustment, per-month correction, interest, and penalty. This clearly distinguishes it from broader sibling tools like calculo_revisional or calculo_atualizar by narrowing the scenario to overdue rent.

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 description gives clear context: it is for overdue rent ('Aluguéis em atraso') and names the governing law, making the primary use case obvious. It does not explicitly name alternatives or state when not to use it, so it stops short of a 5.

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