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Dados B3

by io.github.Val7h
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Fundos de investimento: cota, PL e captação (CVM)

fundos_investimento
Read-onlyIdempotent

Fundos de investimento da CVM (renda fixa, multimercado, ações): cota, patrimônio, cotistas e captação. Use quando: "quais fundos mais captaram este mês?"; "patrimônio do fundo Verde"; "série da cota do fundo CNPJ X". NÃO use para: fundo imobiliário listado (FII) → fii; ETF listado → etf; quais fundos têm uma ação → fundos_da_acao. Fonte e fórmula: Informe Diário da CVM (ODbL); captação líquida = captação − resgate; a variação mensal da cota é conta nossa, não a rentabilidade oficial. Retorna: sem argumento: maiores_pl, maior_captacao_liquida, maior_resgate_liquido; cnpj: o fundo com série de 13 meses; busca: por nome. Vazio ou erro: busca sem resultado: tire acento ou use o começo do CNPJ. limite vai de 1 a 500. Acesso: Gratuita, sem chave.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "fundos_investimento"
  }
}

Input Schema

NameRequiredDescriptionDefault
cnpjNoCNPJ do fundo ou da classe com 14 dígitos; devolve a série de 13 meses.
buscaNoNome do fundo (sem acento e sem distinção de caixa) ou começo do CNPJ.
limiteNoQuantidade de fundos em cada ranking (padrão 20).

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed3 schema fields changed
    • addedInput schema / properties / busca / description
      Added value: +"Nome do fundo (sem acento e sem distinção de caixa) ou começo do CNPJ."
    • addedInput schema / properties / cnpj / description
      Added value: +"CNPJ do fundo ou da classe com 14 dígitos; devolve a série de 13 meses."
    • addedInput schema / properties / limite / description
      Added value: +"Quantidade de fundos em cada ranking (padrão 20)."
  2. Added

TDQS

A4.8/5.0
Behavior5/5

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

Annotations already declare readOnly/idempotent/non-destructive, and the description goes well beyond them: it names the data source (Informe Diário CVM, ODbL), discloses the derived formula (captação líquida = captação − resgate), and warns that the monthly cota variation is the tool's own calculation rather than official rentabilidade. It also states free access with no key and the error behaviour for empty searches, which annotations do not cover.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose, then labelled sections (Use quando / NÃO use / Fonte e fórmula / Retorna / Vazio ou erro / Acesso) that let an agent skim. It is dense and telegraphic rather than wasteful, though the compression means a reader must parse several short fragments per line.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 3-parameter, optional-argument tool with no output schema, it covers everything needed: what each mode returns, the derived-metric caveat, empty-result recovery advice, quota limits and auth requirements. Nothing an agent needs in order to call it correctly or interpret the response appears to be missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema already documents cnpj, busca and limite, making 3 the baseline. The description adds real value on top: it explains what the no-argument call returns (maiores_pl, maior_captacao_liquida, maior_resgate_liquido), ties cnpj to a 13-month series and restates the 1-500 limite range, but does not clarify how cnpj and busca interact if both are supplied.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific resource (CVM investment funds) plus the exact data dimensions covered: cota, patrimônio, cotistas and captação, with the fund categories (renda fixa, multimercado, ações) named. It also explicitly excludes three sibling scopes (fii, etf, fundos_da_acao), so an agent can distinguish it from neighbours without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides three concrete 'Use quando' example queries (top captação, patrimônio of a named fund, cota series by CNPJ) that map onto the three parameter modes. It then gives explicit 'NÃO use para' routing to fii, etf and fundos_da_acao, which is exactly the when-not guidance the dimension asks for.

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

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