bcb_moedas

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

With no annotations provided, the description carries the full burden of behavioral disclosure. 'Lista' clearly implies a read-only operation, and the source (Banco Central) and type (moedas com cotação PTAX) are stated. However, it does not disclose potential limitations such as data volume, rate limits, or the exact structure of the returned list, which would be expected for a listing 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, efficient sentence that front-loads the core action and resource. There is no redundant information or filler, making it appropriately concise and well-structured for quick parsing by an agent.

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?

Given the tool has no parameters and has an output schema (though not detailed), the description provides sufficient context for a basic listing operation. It names the data source (Banco Central) and the specific type (moedas com cotação PTAX), which is adequate for understanding the tool's scope. It could be more complete by explicitly stating that this is for listing available currencies for use in other BCB tools, but this is a minor gap.

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 tool has zero parameters, and the schema confirms this with 100% coverage. The baseline for 0 parameters is 4, and the description appropriately adds no parameter-specific details since none exist. It effectively communicates that no input is required, beyond the implicit context of the tool's purpose.

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 the verb 'Lista' and the resource 'moedas com cotação PTAX disponíveis no Banco Central', making the purpose specific and distinct from vague alternatives. However, it does not explicitly differentiate from sibling tools like bcb_cambio or bcb_serie, which could be confused for similar financial data operations.

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 offers no guidance on when to use this tool versus its siblings. It simply states what it does, leaving the agent to infer usage context. There is no mention of exclusions or alternative conditions, so agents may not know when this listing is preferred over bcb_cambio or bcb_serie.

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