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

Annotations already declare readOnly, idempotent, non-destructive. The description adds behavioral context beyond annotations: it is hosted by the platform, requires no platform credentials but does require user credentials (implicit via parameters), costs per query, and involves LGPD responsibilities. It clearly states the data is not confidential and is the same available to citizens. This adds useful operational and legal transparency.

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 concise paragraph that front-loads the core purpose and then provides operational context (payment, official source, LGPD). It has no filler or repetition, though it could be slightly more structured but remains appropriately brief.

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?

Given the tool has 6 parameters, no output schema, and no parameter descriptions, the description is incomplete. It does not explain what the response contains, how pagination works (pagina), or how to provide credentials (login vs pkcs12). The complexity of the tool demands more detail on usage and return expectations, which the description fails to supply.

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 by explaining parameters. It does not mention any of the six parameters (cnpj, pagina, login_cpf, login_senha, pkcs12_cert, pkcs12_pass). While some parameter names are self-explanatory, the description adds no semantic value beyond what the schema itself shows, leaving ambiguity about required formats or usage.

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: 'Meus Veículos - Possuidor (Listagem), consulta em fonte oficial' – a query for listing vehicles held by the possessor from an official source. It distinguishes from unrelated siblings like authenticate or connect, and the name itself reinforces the function.

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 provides usage context such as 'sem credenciais da plataforma', 'pague por consulta com crédito pré-pago', and notes it queries official Brazilian sources. It implicitly indicates a paid, on-demand query, but does not explicitly state when to use it over alternatives or exclusions. Since no similar sibling tools exist, the guidance is adequate though not exhaustive.

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