bcb_focus_selic

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

Beyond the annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint), the description discloses valuable behavioral traits: vintage semantics (coletadoEm vs referencia), the fact that counting is done on the client side because $count is ignored, the mandatory filter requirement, the 30-day default window, and that microdata are not exposed due to confidentiality. No contradictions.

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 lengthy but well-structured with clear sections (Quando usar, Quando NÃO usar, Retorna). Every sentence adds information relevant to using the tool correctly, but it could be slightly tightened without losing value. The organization aids comprehension.

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 tool with 5 parameters, rich annotations, and an output schema, the description covers all essential aspects: purpose, usage, defaults, return fields, data quirks, and limitations. It leaves no significant gap for an agent to misuse the 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 description coverage is 100%, so the schema already documents all parameter names, defaults, formats, and constraints. The description adds useful context (e.g., the 30-day default window, the format for reuniao), but this is marginal beyond what the schema already provides. Thus, baseline 3 is appropriate.

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 and resource: 'Consulta as expectativas de mercado do Focus para a taxa Selic, organizadas pela REUNIÃO do Copom.' It clearly differentiates from the sibling bcb_focus_expectativas by explicitly stating the temporal axis is the Copom meeting, not the calendar, and even names the alternative tools.

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?

It provides explicit when-to-use ('Quando usar: ...') and when-not-to-use ('Quando NÃO usar: ...') guidance, naming specific siblings (bcb_focus_expectativas, bcb_serie_valores) with codes, and explains the separation rationale. This is model guidance.

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