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

The readOnlyHint annotation already indicates a safe read operation, and the description adds context about using the official Receita Federal API. However, it does not disclose limitations, rate limits, or what 'calcular' involves beyond querying rates, so it adds only modest behavioral context beyond the annotation.

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 two short sentences, front-loaded with the core action and resource, and every word adds relevant information. 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?

For a tool with 6 parameters and no output schema, the description provides only high-level intent and data source. It does not clarify expected return values, how to choose between NCM and service code, or the role of origin/destination fields. While the schema covers parameter names, the operational context is incomplete.

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 coverage is 100%, so each parameter has a description. The tool description adds slight nuance by mentioning 'produto (NCM) ou serviço', which clarifies the ncm and codigoServico parameters, but it does not explain parameter interactions or optionality beyond the schema. Baseline of 3 is appropriate.

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 verb ('Calcula') and resource ('alíquotas CBS e IBS'), narrowing to product (NCM) or service, and distinguishes itself from sibling tools like 'consultar_aliquota_cbs_ibs' by using 'calcular' instead of 'consultar'. It also mentions the legal basis (LC 214/2025) and the official API source.

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 implies use for calculating tax rates but provides no explicit guidance on when to choose this tool over similar siblings such as 'consultar_aliquota_cbs_ibs' or 'simular_imposto_reforma'. No exclusions or alternative recommendations are given, leaving usage context vague.

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