comex_freight_cost

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

With no annotations, the description carries the behavioral disclosure burden. It discloses the data source (VL_FRETE and VL_SEGURO fields), the fact it is import-only, that air is corrected by despatch point, and the output units (US$/kg and % of FOB). It does not describe the response shape or potential limitations like missing data or aggregation behavior, but the key behavioral facts are present. A score of 4 reflects that the description goes beyond a bare statement of function.

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?

Three sentences, each earning its place: the first defines the product and units, the second explains provenance and why it is valuable, the third states constraints (import-only and air correction). It is front-loaded with the core definition and avoids redundant words. No fluff or repetition of schema content. This is concise and well-structured.

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 has 5 parameters, no output schema, and no annotations. The description effectively communicates what the tool provides, but it does not describe the return format (e.g., whether it returns a table per channel, time series, or aggregated values). Since there is no output schema, the agent is left guessing at the response structure. While the core semantics are clear, the agent may need additional guidance on what to expect, making it incomplete for a complex data tool.

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% for all 5 parameters, so the baseline is 3. The description does not add parameter-specific semantics beyond the schema; it mentions the channel is always included (which relates to group_by) but does not explain details like how NCM prefix matching works or how to combine years/months. The schema already describes each parameter clearly. Thus the description adds no extra value for parameter understanding.

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 names a specific resource (freight and insurance declared to customs by transport channel) and clearly distinguishes it from siblings by emphasizing it is the best systematic measure of realized cost. The verb is implicit ('provides') but the scope and source are explicit. It differentiates itself from comex_trade_flow (which likely covers flows) and comex_data_caveats (which explains caveats). This is a clear, distinct purpose.

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 a clear constraint: only imports, with export files lacking freight. It also states the air channel is corrected, which is a usage detail. It implies the tool should be used when realized cost is needed ('melhor medida sistematica de custo realizado'), but it does not explicitly name alternatives or say when not to use it. Thus it provides clear context and a condition, but stops short of explicit when-to-use vs. when-not-to-use guidance.

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