Vendas de hoje

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

Annotations already provide readOnlyHint and openWorldHint. The description adds specificity: read-only nature, timezone (Brasília), and that it returns only aggregate data. This adds value beyond annotations without contradiction.

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, efficient sentence that front-loads the core purpose, includes key details, and avoids redundancy. Every word contributes clarity.

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 no parameters and no output schema, the description covers the return fields explicitly (total pago, contagem, ticket médio, breakdown, total pendente). It lacks explanation of the exact structure or format, but the listed fields provide sufficient context for an agent.

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?

No parameters exist, and schema coverage is 100%. The description explains what the tool returns, fulfilling the need for parameter semantics since there are none to describe.

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 it provides an aggregate summary of daily sales (Brasília time) for the authenticated ZuckPay account, specifying included metrics (total paid, count, average ticket, payment method breakdown, pending total) and explicitly excluding individual transactions and buyer data. This distinguishes it from sibling tools like listTransactions.

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 usage for a quick daily sales overview and explicitly states what it does not return (individual transactions or buyer data), guiding the agent to alternatives. However, it does not explicitly name those alternatives, leaving some inference needed.

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