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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive/non-open-world, so the safety profile is covered. The description adds real value beyond that: it discloses the computed fields returned, the Shopee-only bonus-tier behavior, and the empty-result semantics (nenhuma meta definida). It could still mention currency/timezone or freshness but does well.

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 tight sentences, front-loaded with the resource and its scope, then the Shopee special case and empty-state note. No filler, every clause conveys information.

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 no output schema, the description carries the burden of explaining the response and it names the metrics returned plus the empty-list case. Gaps are minor: it does not state which marketplaces/currencies or whether data is current-month-to-date, but an agent has enough to call and interpret it.

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 tool takes zero parameters, so there is nothing to disambiguate and no schema gap to compensate for; baseline 4 applies. The description correctly signals the implicit scope (current month, per marketplace) that otherwise would be a hidden filtering assumption.

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?

States a specific verb/resource: sales goals (GMV) for the current month, broken down by marketplace, with the fields returned (realizado, % atingido, falta, falta/dia) and a Shopee-specific extra (faixas do bônus). No sibling tool covers goals, so it is unambiguously distinguishable from the comparison/breakdown/list siblings.

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?

Usage is only implied — an agent infers it should call this when the user asks about monthly targets, but there is no explicit when-to-use or when-not framing. The note that an empty list means no goal was defined (user sets them in the Metas panel) is helpful context but is about interpreting output, not about tool selection.

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