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

The readOnlyHint annotation already declares this is a safe read-only operation, so that aspect is covered. The description adds value by explaining the comparative nature (new CBS/IBS vs current taxes), but it does not disclose conditional parameter dependencies (e.g., NCM required for mercadoria, codigoServico for servico) or what the output will specifically include beyond a comparison.

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, focused sentence. It front-loads the action ('Simula') and clearly conveys the scope and comparison. There is no redundancy or irrelevant information, making it highly efficient.

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 has 7 parameters, no output schema, and moderate complexity. The description provides a high-level purpose but is thin on conditional requirements—such as which parameters are needed for each tipoOperacao. The schema offers hints ('para mercadorias', 'para serviços') but the description itself does not reinforce this, leaving gaps for an agent to understand how to structure a valid request across operation types.

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 baseline is 3. The description's mention of CBS/IBS and current taxes gives context, but it does not add parameter-specific semantics beyond what the schema fields already say (e.g., amount, operation type, regime). The tool's behavior regarding interactions between parameters is not clarified further.

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 clearly states a specific action (simulates) and resource (impact of Tax Reform with CBS + IBS) and explicitly compares with the current regime (PIS/COFINS/ISS/ICMS). This distinguishes it from sibling tools like calcular_cbs_ibs, which focuses on calculating a specific tax, and simular_regime_tributario, which simulates regime choice.

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 intended usage is implied by the description—simulating the impact of the tax reform—but there is no explicit guidance on when to use this tool versus alternatives such as calcular_cbs_ibs or consultar_aliquota_cbs_ibs. No exclusion criteria or alternative tool mentions are provided, leaving the choice somewhat ambiguous.

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