MCP CNPJ Intelligence

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

With no annotations provided, the description carries full burden and does well by specifying what information is returned (simples_nacional, mei, dates). However, it doesn't mention potential limitations like rate limits, authentication requirements, or error conditions that would be helpful for a production agent.

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 perfectly structured with clear sections (purpose, usage guidelines, return values) and every sentence earns its place. It's front-loaded with the core purpose and uses bullet points efficiently without any wasted words.

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 single-parameter lookup tool with no output schema, the description provides excellent context about what the tool does, when to use it, and what it returns. The only minor gap is lack of information about error handling or edge cases, but overall it's quite complete for this complexity level.

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% with the single 'cnpj' parameter well-documented in the schema. The description doesn't add any additional parameter information beyond what's in the schema, which is acceptable given the high coverage. Baseline 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 the tool's purpose with specific verbs ('verifica regime tributario') and resources ('Simples Nacional ou MEI'), distinguishing it from siblings like 'buscar_empresa' or 'empresa_completa' which have broader scopes. It explicitly identifies the two specific tax regimes it checks.

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 'QUANDO USAR' section provides explicit guidance on when to use this tool: for checking if a company can issue simplified invoices or filtering companies by tax regime. It clearly distinguishes use cases from other tools that perform general searches or lookups.

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