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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read-only operation. The description adds tax scope but does not disclose what happens to the generated guide (e.g., returned as PDF, saved to a file) or any prerequisites. With annotations covering the key behavioral trait, a 3 is appropriate.

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 a single concise sentence that front-loads the action ('Gera guias DARF') and includes only relevant detail about taxes and context. No filler or redundancy.

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 with two well-documented parameters and a read-only annotation. The description states the purpose and context adequately, but it does not mention what the generated guide looks like or how it is delivered (e.g., download link, PDF). For a generator tool, this is a noticeable gap, but the core functionality is still clear enough for basic use.

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?

The input schema provides 100% coverage with descriptions for both parameters (empresaId and competencia), including format. The description does not add any parameter-specific semantics beyond what the schema already states, so the baseline 3 is retained.

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 'Gera' with a clear resource 'guias DARF' and specifies the exact tax types (IR, PIS, COFINS, CSLL) and context (serviços tomados). This distinguishes it from sibling tools like emitir_nfse or calcular_cbs_ibs, making its purpose unmistakable.

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 provides clear usage context: generate DARF guides for withheld taxes on services taken. It does not explicitly name alternatives or exclusions, but the context is specific enough that an agent can infer when it applies. This aligns with 'clear context, no exclusions'.

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