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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description adds valuable behavioral context about data freshness, file availability timing, and the 92-day cap. It also previews the response shape via 'detalhadas e totalizadas por data'. It does not cover empty-result or error behavior, but the annotations lower the burden.

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 dense Portuguese sentences carry only essential information: purpose, data freshness constraint, and maximum range. There is no filler, repetition, or irrelevant context. The most decision-relevant facts are placed prominently.

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 read-only date-bounded query, the description covers the returned data, the effective data latency, and the maximum call window, which is enough for most real usage. The absence of an output schema is partially mitigated by the mention of per-date detail and totals. The remaining gap is the undocumented meaning and format of the account parameter.

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 has 0% description coverage for its three string parameters, so the description must compensate. It clarifies that data_inicio and data_fim form a date window limited to 92 days with a default ending yesterday. However, it does not explain the account parameter or the expected date format, leaving a meaningful gap.

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 explicitly defines the tool as Stone's receivables agenda: unpaid installments with expected payment dates, detailed and totalized by date. The phrase 'ainda não pagas' semantically distinguishes it from sibling tools like stone_vendas_liquidacoes or stone_vendas_cancelamentos. The purpose is unmistakable even without an explicit verb.

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 gives clear invocation context: Stone's daily file is only ready after 5h of the following day, so data should be expected only up to yesterday, and a single call is limited to 92 days. This helps the agent decide when results are current and when requests need to be split. It does not explicitly name alternative tools for when-not-to-use scenarios.

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