# calcular_porcentagem

Calcula porcentagens em 5 modos: X% de Y, X é quantos % de Y, variação %, aumentar ou diminuir por %.

Agent View of the PolicyLayer registry record for `calcular_porcentagem`. HTML page: https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-porcentagem

## Facts

- Tool: `calcular_porcentagem`
- Server: Contaí — Calculadoras Fiscais Brasileiras (`@contai-evoluke/mcp-server`) — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server.md
- Install: `npx -y @contai-evoluke/mcp-server`
- Homepage: https://github.com/lfhillesheim/calculadora
- Risk category: Read (Low risk)
- Registry record: grade B, identity unverified
- Server rate-limited: no
- Parameters: 3 (3 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `a` | number | yes | Primeiro valor (base ou numerador conforme o modo) |
| `b` | number | yes | Segundo valor (total, taxa ou variação conforme o modo) |
| `operation` | string | yes | Modo: percent_of (X% de Y), what_percent (X é quanto % de Y), percent_change (variação %), increase_by (aumentar por %), decrease_by (diminuir por %) |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "calcular_porcentagem",
    "arguments": {
      "a": 0,
      "b": 0,
      "operation": "<operation>"
    }
  }
}
```

## Why calcular_porcentagem is rated Low

This is a pure calculation utility that reads input values and returns computed percentages. It has no side effects, does not modify data, execute code, delete anything, or involve financial transactions. The most severe effect of misuse would be incorrect calculations, which is informational only. Classified as Read with low severity.

From the tool's own definition: "Tool name 'calcular_porcentagem' and description indicate it performs percentage calculations (X% of Y, variation %, increase/decrease by %) with no modification of external state or data. It retrieves computed results based on inputs."

## Use case

AI agents call calcular_porcentagem to retrieve information from Contaí — Calculadoras Fiscais Brasileiras without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Contaí — Calculadoras Fiscais Brasileiras:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "calcular_porcentagem": {}
  }
}
```

## Other tools on Contaí — Calculadoras Fiscais Brasileiras (138)

- `calcular_mensalidade_planejador` — Financial — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-mensalidade-planejador.md
- `buscar_lei` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/buscar-lei.md
- `calcular_13o_salario` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-13o-salario.md
- `calcular_acao_trabalhista` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-acao-trabalhista.md
- `calcular_adicional_noturno` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-adicional-noturno.md
- `calcular_alocador_50_30_20` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-alocador-50-30-20.md
- `calcular_aluguel_reajuste` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-aluguel-reajuste.md
- `calcular_aluguel_vs_compra_imovel` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-aluguel-vs-compra-imovel.md
- `calcular_auditoria_beneficios_trabalhistas` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-auditoria-beneficios-trabalhistas.md
- `calcular_auxilio_doenca` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-auxilio-doenca.md
- `calcular_aviso_previo` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-aviso-previo.md
- `calcular_banco_de_horas` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-banco-de-horas.md
- `calcular_bdr_vs_etf_vs_acao_direta` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-bdr-vs-etf-vs-acao-direta.md
- `calcular_bola_de_neve_dividas` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-bola-de-neve-dividas.md
- `calcular_bolsa_estagio` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-bolsa-estagio.md
- `calcular_calculadora_gestacional` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-calculadora-gestacional.md
- `calcular_calculadora_milhas_passagem` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-calculadora-milhas-passagem.md
- `calcular_calorias_macros` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-calorias-macros.md
- `calcular_capital_de_giro_necessario` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-capital-de-giro-necessario.md
- `calcular_carne_leao` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-carne-leao.md
- `calcular_cartao_credito_cashback_anuidade` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-cartao-credito-cashback-anuidade.md
- `calcular_cdb_vs_lci_vs_tesouro_vs_poupanca` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-cdb-vs-lci-vs-tesouro-vs-poupanca.md
- `calcular_comparador_regime_tributario` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-comparador-regime-tributario.md
- `calcular_consorcio_credito_empresarial` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-consorcio-credito-empresarial.md
- `calcular_consorcio_vs_financiamento` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-consorcio-vs-financiamento.md
- `calcular_consultoria_pj_saude_financeira` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-consultoria-pj-saude-financeira.md
- `calcular_consumo_agua` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-consumo-agua.md
- `calcular_conversao_moedas_iof` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-conversao-moedas-iof.md
- `calcular_credito_pj_comparador` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-credito-pj-comparador.md
- `calcular_custo_efetivo_total` — Read — https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server/calcular-custo-efetivo-total.md
- …and 108 more: https://policylayer.com/tools/io-github-lfhillesheim-contai-mcp-server.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-lfhillesheim-contai-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-lfhillesheim-contai-mcp-server