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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description adds value by detailing grouping behavior (agrupa as vendas por destinatário/CNPJ-CPF) and ordering (ordenados por valor). It also implicitly indicates a filtered date range through 'no período,' offering additional context beyond annotations.

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 two concise sentences, front-loaded with the core purpose and result. Every word adds value, with no redundancy or filler.

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 5 parameters and no schema descriptions, the description should provide substantial parameter context but does not. It lacks explanations for loja, account, top, and the date range parameters, making the tool difficult to invoke correctly without external knowledge. The output is also not described, though no output schema exists.

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 explain the parameters, but it only refers to 'período' and 'maiores compradores' without mapping to data_inicial, data_final, top, loja, or account. This leaves parameter meanings entirely undefined, failing to compensate for the 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 clearly states the tool ranks clients by sales value over a period, groups by recipient/CNPJ-CPF, and returns top buyers ordered by value. It is specific and distinct from sibling sales tools, which focus on individual transactions or summaries rather than client ranking.

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 when to use it (ranking clients by sales), but provides no explicit guidance on when not to use it or which alternative to choose. Given many sibling sales tools (e.g., cigam_vendas, cigam_vendas_resumo, cigam_vendas_por_dia), clearer differentiation would be beneficial.

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