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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: the catalog is local and makes no network call, provenance is explained through 'fonteNome' with 'portal' vs 'medido', and the return shape changes based on whether a filter is applied. This goes well beyond what annotations provide and contains no contradiction with them.

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 front-loaded with the main purpose and use guidance, and every sentence contributes substantive information. However, it is a single dense paragraph combining purpose, return shape, provenance, and exclusions; more visual structure would improve scanability without losing information.

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 description covers the catalog size, grouping behavior, filter behavior, return fields, local-network behavior, provenance semantics, and exclusions. The main gap is the inconsistent treatment of 'Expectativas': the schema lists it as a valid category, while the description says Focus expectations are not here. This ambiguity could confuse an agent choosing a filter value.

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 parameter is already documented well. The description adds little beyond what the schema says: it mentions the category filter and lists some categories, but that information essentially repeats the schema. The category list in the description also diverges from the schema by omitting 'Índices de Mercado' and 'Expectativas', so it does not reliably enhance 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 opens with a specific verb and resource: it lists a curated internal catalog of 135 BCB economic series with codes, grouped by category, and accepts a category filter. It explicitly contrasts itself with bcb_buscar_serie and bcb_focus_expectativas, making sibling differentiation clear. The category list is slightly inconsistent with the input schema, but the core purpose is 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 provides explicit 'Quando usar' and 'Quando NÃO usar' guidance, names the alternative for keyword search (bcb_buscar_serie), and warns that this tool does not fetch values. It also tells users that Focus expectations are not included and routes them to bcb_focus_expectativas. This is strong, actionable usage guidance.

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