Obter XML da NFS-e

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

With no annotations, the description carries the transparency burden and does disclose the output nature: raw XML in national NFSe layout. However, it says nothing about auth requirements, invalid-key behavior, or whether the XML is returned inline or as a file, leaving meaningful behavioral gaps.

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 with no filler. It front-loads the verb and resource, then immediately gives the lookup key.

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 simple one-parameter retrieval tool, the description names the required input and the return type sufficiently for a correct call. There is no output schema, so the explicit mention of 'XML bruto (bloco NFSe, layout nacional)' compensates; only error/not-found behavior is left unspecified.

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 schema already describes 'chave' as the 50-digit access key, and the description only restates that lookup is by access key. With 100% schema description coverage, the description adds no extra parameter semantics beyond what the schema provides.

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 names a specific action ('Retorna o XML bruto') and a specific resource ('de uma nota pela chave de acesso'), making the tool's function immediately clear. It does not explicitly contrast itself with siblings like nfse_consultar_por_chave, so it falls short of full differentiation.

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 phrase 'pela chave de acesso' clearly identifies the required input and the conditions under which the tool applies: retrieving a specific invoice's raw XML by its access key. It does not mention when to prefer an alternative sibling, so it stops short of full routing guidance.

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