futuros_b3

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

With no annotations, the description carries the full burden. It indicates a read-only data retrieval operation ('Daily settlement prices'), lists parameters, and gives examples. It does not mention authentication, rate limits, or error behavior, but for a simple query tool, these omissions are acceptable. No contradiction with annotations (none present).

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 concise: a single sentence stating purpose, a comma-separated list of contracts, and two parameter lines. No wasted words. The most important information is front-loaded.

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?

For a simple data retrieval tool with an output schema present (context signal), the description covers input parameters, valid contracts, and date format. No further details about return values are needed. The description is complete enough for an agent to use the tool effectively.

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 input schema has 0% description coverage, leaving the description to explain parameters fully. The description adds value by listing valid contract names, specifying the date format 'YYYY-MM-DD' with a default of today, and providing examples (e.g., 'milho'). This is far 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 clearly states it provides 'Daily settlement prices for agricultural futures on B3 exchange' and lists specific contracts (e.g., boi_gordo, milho). This distinguishes it from siblings like preco_diario, which likely handles spot prices. The verb+resource combination is specific and unambiguous.

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 implicitly suggests use for retrieving agricultural futures settlement prices, but does not explicitly state when to use this tool versus alternatives like preco_diario or balanco. No exclusions or context for when not to use are provided.

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