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

No annotations exist, so the description carries the full disclosure burden and does so thoroughly: it explains the ~100-day CVM publication lag, the `disponivel_em` field, survivorship bias in the universe, exclusion of flagged values, and the `chave_api` requirement. These are behavioral facts an agent could not infer from the schema.

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 dense and every sentence carries useful information, and the core purpose is front-loaded. However, it is a long single paragraph; the `as_of` explanation is especially heavy and could be structured as a short list 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?

Despite having no output schema, the description covers everything needed to invoke the tool correctly: filter syntax, date modes, exclusions, bias caveat, and auth. It even mentions the `disponivel_em` field in the response, so the agent is not left completely blind about output shape.

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?

With 0% schema description coverage, the description compensates fully: it explains the `filtros` dict with a concrete example, enumerates every supported indicator and the _min/_max suffix convention, and clarifies `ano` vs `as_of` semantics. The only minor issue is that `chave_api` is described as required while the schema gives it a default and does not require it, but this does not reduce the semantic value added.

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 verb and resource: 'Filtra as AÇÕES do universo por faixas de indicadores'. It also immediately distinguishes itself from `screener_fiis`, so an agent can tell exactly what this tool does without opening the schema. There is no ambiguity about the stock universe.

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 gives explicit when-to-use and when-not-to-use guidance: stocks only, with FIIs routed to `screener_fiis`. It also tells the agent when to use `as_of` ('para pesquisa sem olhar o futuro') and states that `ano` and `as_of` cannot be combined, which prevents an obvious misuse.

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