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

With no annotations, the description carries the full disclosure burden. It usefully discloses that only current/valid offers ('ofertas vigentes') and only supermarkets accompanied by the service are considered. It does not describe output structure, ordering, or matching behavior, but these are minor gaps for a read-only comparison tool.

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, compact sentence that front-loads the core action and includes geographic and scope constraints without any filler or repetition.

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 tool is simple, with one fully documented parameter, so the description is mostly adequate for invoking it. However, without an output schema or sibling routing, it does not specify what the returned comparison contains or how this tool differs from search_offers/top_offers, leaving some gaps in contextual completeness.

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 100%: the single parameter 'product' already has a description ('Produto que será comparado entre mercados'). The tool description adds no additional semantic detail beyond what the schema provides, so the baseline score applies.

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 ('Compara') and a clear resource: current offers of a product across supermarkets tracked by Menor Preço Hoje in Lages, SC. This distinguishes it from siblings like best_price or list_markets without merely restating the tool name.

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 intended use case is implied: when an agent needs to compare a product's current offers across supermarkets. However, there is no explicit guidance on when to prefer this tool over siblings like search_offers, top_offers, or best_price, and no exclusions are stated.

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