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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds the ordering semantics but says nothing about pagination, result freshness, or how openWorld lookups behave (latency, coverage of categories), which would be the value-add 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?

A single front-loaded sentence with no waste. The three category examples in parentheses are partly redundant with the 27-value enum in the schema, which is the only mild inefficiency.

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 annotations covering safety, a fully enumerated parameter set, and no output schema to explain, the description gives enough to call the tool correctly. Only the absence of any alternative-routing guidance for the four sibling tools keeps it below the top mark.

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 coverage is 50%: limite and preco_maximo carry their own descriptions and categoria/ordem are enums with defaults. The description reinforces that preco_maximo is optional and glosses 'desconto' as biggest discount and 'vendidos' as best sellers, but adds no format or interaction details beyond the schema.

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 ('Melhores ofertas de uma categoria') plus the sort dimensions and the optional price cap, so an agent knows exactly what it returns. It never names or contrasts with the siblings (buscar_ofertas, ofertas_em_alta, search, fetch), so differentiation is left to inference.

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 implied by 'de uma categoria ... por maior desconto ou mais vendidos', which suggests browsing a category sorted by discount or popularity. There is no explicit when-to-use/when-not statement and no pointer to an alternative such as buscar_ofertas for keyword searching.

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