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

Beyond the readOnly/idempotent/destructive annotations, it discloses client-side pagination behavior, a 15-minute cache, and a specific LGPD limitation: `infcomplementar` may contain unstructured server names and SIAPE numbers that masking does not cover. These are exactly the behavioral and data-sensitivity traits an agent needs before invoking or interpreting results.

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?

Three short, front-loaded sentences: purpose and endpoint first, then behavior, then a necessary privacy caveat. No redundant restatement of schema or annotations; every sentence earns its place.

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 read-only list operation with an output schema and rich annotations, the description covers purpose, endpoint, pagination model, cache freshness, and a data-protection caveat. Nothing an agent needs to invoke or interpret the result correctly appears to be 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?

Schema coverage is 100%, so the schema already documents `id_contrato`, `pagina`, and `tamanho_pagina`. The description adds the key semantic that pagination is client-side, which changes how an agent should interpret `pagina` and `tamanho_pagina`, and it flags the sensitive `infcomplementar` field relevant to interpreting returned data.

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?

Description opens with 'Lista NFs/faturas' and the exact endpoint `/api/contrato/{id}/faturas`, giving a specific verb and resource. This clearly distinguishes it from sibling contract-subresource tools like `compras_contrato_empenhos` or `compras_contrato_garantias`, even though no sibling is named.

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 stated purpose 'Lista NFs/faturas' gives clear context for when to call it: whenever invoices/NFS for a contract are needed. It does not explicitly name alternatives or state when not to use it, but among the many contract-related siblings the resource term is unambiguous.

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