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

No annotations are provided, so the description carries the full burden. It does disclose the data source, the geographic scope, and that the price is current ('vigente'). However, it does not describe the return shape, no-result behavior, or any limitations, which would be useful given the absence of an output schema.

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 with no filler. The core action and scope are front-loaded, followed by a practical usage trigger. Every word earns its place.

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?

The description covers what the tool does, where it applies, and when to use it. However, with no annotations and no output schema, it fails to specify what the response contains (e.g., store, price, date) or what happens when no matching price is found, which leaves a noticeable gap 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?

Schema description coverage is 100%, and the schema already documents the 'product' parameter with an example. The description adds contextual framing (Lages, lowest current price) but no additional parameter-level semantics beyond what the schema provides.

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 uses a specific verb ('Encontra') and names the exact resource: the current lowest price of a product in Lages, Santa Catarina, from a defined data source. It clearly communicates what the tool does and is conceptually distinct from the sibling tools, though it does not explicitly contrast itself with them.

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 an explicit trigger: 'Use quando o usuário perguntar onde determinado produto está mais barato.' This is clear and actionable. It does not mention when not to use the tool or name alternatives, so it stops short of a perfect score.

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