Br Build Access Key

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

With no annotations, the description carries the behavioral disclosure burden. It makes clear this is a construction/computation utility rather than a submit/sign tool, and it explicitly discloses the cnf generation behavior and output structure. A brief statement that it has no external side effects would make it stronger, but 'Assemble' and 'Returns a dict' imply a pure in-memory operation.

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?

Two focused sentences: the first front-loads the core purpose, the second gives the return contract. There is no filler or redundant restating of the tool name.

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 input schema fully documents all required and optional parameters, the description explains the output and the optional-generation behavior, and the output schema is present. For a self-contained key-building utility, nothing necessary for correct invocation is missing.

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 covers all parameters with descriptions (100% coverage), so the baseline is 3. The description adds little beyond the schema: the only parameter-specific detail is cnf, and that is already described in the schema as 'Gerado se omitido'.

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 action ('Assemble and check-digit') on a precise resource (the 44-character NF-e/NFC-e access key/chNFe) and names the exact return fields. This clearly distinguishes it from sibling validation, generation, and submission tools.

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: use this when an NF-e/NFC-e access key needs to be assembled, likely before document generation or signing. However, it does not explicitly state when to prefer this over generate_nfe, nor does it mention any prerequisites or exclusions.

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