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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds the legal reference and 'vigentes' (current), which implies time-sensitive data, but it does not disclose parameter combination behavior, output format, or any constraints. Minimal additional context beyond 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 a single, well-structured sentence front-loaded with the verb 'Consulta'. Every word is purposeful, and it includes the legal reference without bloat.

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 4 optional parameters and no output schema. The description does not explain what inputs are needed for product vs service queries, what the return data looks like, or what happens when no parameters are provided. This leaves significant gaps for an agent to invoke the tool correctly.

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 descriptions cover all 4 parameters (100% coverage), so baseline is 3. The description mentions product vs service but does not explain which parameters apply to each scenario or how they interact (e.g., ncm with ufDestino vs codigoServico with codigoMunicipio). No extra semantic value over schema.

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 ('Consulta') and resource (CBS/IBS rates) for a specific service or product, with legal reference LC 214/2025. It clearly identifies the operation but does not explicitly distinguish this from sibling tools like 'calcular_cbs_ibs' or 'simular_imposto_reforma'.

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 no guidance on when to use this tool versus alternatives such as 'calcular_cbs_ibs' or 'simular_imposto_reforma'. There is no mention of scenarios, prerequisites, or exclusions, leaving the agent to infer usage.

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