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

The annotations already declare the operation as read-only, idempotent, and non-destructive, so the description does not need to restate those. It adds value by noting the tool returns specific invoice fields and is scoped by store and period, but it does not disclose behavior such as pagination, status filtering, or response format details.

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 that front-loads the action and resource. It provides the most important information without 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 9-parameter tool with no output schema, the description is too minimal. It does not explain the purpose of pagination, filters, or account/referenca fields, and it leaves the response format ambiguous with 'etc.' This is inadequate for an agent to use the tool correctly in varied scenarios.

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 0%, so the description must compensate, but it only clarifies the meaning of 'loja' and the period concept (data_inicial/data_final) implicitly via 'por período'. The remaining 7 parameters (page, limit, status, account, numero_nf, referencia) are completely unexplained, leaving major gaps.

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 uses a specific verb 'Lista' and identifies the resource as 'notas fiscais de uma loja por período', making the tool's function unambiguous. It also lists the key return fields (número, série, destinatário, valor, status, chave NF-e), which distinguishes it from sibling tools like cigam_vendas or cigam_compras.

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 the tool is used to list invoices for a store within a time period, but it provides no explicit guidance on when to choose this tool over alternatives or any exclusions. No alternatives are mentioned, and the 'when to use' is only implicit.

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