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

With no annotations provided, the description carries the full burden of behavioral disclosure. It communicates the analysis nature of the tool (comparing two regimes and summing DAS, INSS, IRPF), which is useful. However, it does not disclose the return format, whether results favor one scenario, or any limits/edge cases — moderate coverage for a calculator with no annotation safety signals.

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?

Three sentences with the core purpose front-loaded before the parameter guidance. The parameter list slightly overlaps with what the schema already encodes (required/optional), but the text is otherwise tight and free of filler, keeping the definition compact.

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 fairly complex tax tool, the description captures the essential calculation logic (comparison of Anexo V minimum-wage vs. Anexo III 28% pró-labore, summing DAS, INSS, IRPF). There is no output schema, and the description does not describe the result format, but the 100% parameter schema coverage and the clear narrative make the tool adequately specified for correct invocation.

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%, so the schema already documents all three parameters with full descriptions, placing the baseline at 3. The description adds marginal value by flagging required vs. optional params (already in the schema's 'required' array) and by advising to 'use exactly these names, in English' — a modestly helpful hint given the Portuguese narrative. It does not compensate beyond the schema needs.

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 uses a specific verb plus resource ('Calcula o pró-labore ótimo') and scopes it precisely to a service company subject to the Fator R regime. It states the exact comparison being made (minimum-wage Anexo V vs. Anexo III at the 28% threshold) and the components summed (DAS, INSS do sócio, IRPF), which clearly differentiates it from siblings like calculate_fator_r (which computes only the ratio) and calculate_simples_nacional.

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 names the applicable scenario — 'empresa de serviços sujeita ao Fator R' — which gives a clear context for when to use the tool. It does not, however, explicitly name a sibling alternative or state when NOT to use it, which would be useful given the closely related calculate_fator_r and calculate_simples_nacional tools.

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