faturas

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so safety behavior is covered. The description adds genuine context beyond them: omitting conta_id widens the result set to all cards, which is a scope behavior an agent must know. It does not mention pagination, rate limits, or authorization needs.

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 short sentences, zero filler, with the resource front-loaded and the parameter behavior immediately after. The first sentence is a bare noun phrase rather than an actionable clause, which slightly weakens the opening.

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?

With an output schema present and rich annotations, the description needn't explain return values or safety. Still, for a tool whose sole parameter is undocumented in the schema, an agent is left guessing what a conta_id refers to, which is a meaningful gap for a 1-param fetch tool.

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% – the only parameter is labeled just 'Conta Id' with no explanation. The description partially compensates by defining omission semantics ('returns from all cards'), but never explains what a conta_id actually is or how to obtain one (presumably via listar_conexoes/listar_contas).

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 resource (credit card statements, 'faturas de cartao de credito') and its retrieval behavior ('traz de todos os cartoes'), which distinguishes it from siblings like transacoes, saldo, and gastos_por_categoria. The verb is only implicit ('traz' rather than 'list'), so it is clear but not maximally precise.

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 second sentence gives a concrete conditional ('Sem conta_id, traz de todos os cartoes'), which tells the agent what happens when the optional param is omitted. However, it never states when to prefer this tool over siblings such as transacoes or listar_contas, nor where a conta_id comes from.

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