calculate_lot_size · MetaTrader 5 MCP Server MCP

WHAT IT DOES

What calculate_lot_size does on MetaTrader 5 MCP Server

AI agents invoke calculate_lot_size to trigger actions in MetaTrader 5 MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why calculate_lot_size needs a policy

The tool exists on a trading/financial server alongside tools like calculate_margin, calculate_profit, and close_position. 'Calculate_lot_size' most likely computes a position size (lot size) for trading purposes. If it only computes/returns a value without placing orders, it would be Read; however, on MT5 servers such functions can trigger order sizing logic or feed directly into trade execution.

From the tool's definition Tool name 'calculate_lot_size' on a MetaTrader 5 trading server; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

calculate_lot_size Rate-limited

calculate_lot_size stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "calculate_lot_size": {
      "limits": [
        {
          "counter": "calculate_lot_size_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches MetaTrader 5 MCP Server, so you can run agents against it safely.

FAQ

Questions about calculate_lot_size

What does the calculate_lot_size tool do? +

calculate_lot_size. It is categorised as a Execute tool in the MetaTrader 5 MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on calculate_lot_size? +

Register the MetaTrader 5 MCP Server MCP server in PolicyLayer and add a rule for calculate_lot_size: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches MetaTrader 5 MCP Server. Nothing to install.

What risk level is calculate_lot_size? +

calculate_lot_size is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit calculate_lot_size? +

Yes. Add a rate_limit block to the calculate_lot_size rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block calculate_lot_size completely? +

Set action: deny in the PolicyLayer policy for calculate_lot_size. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides calculate_lot_size? +

calculate_lot_size is provided by the MetaTrader 5 MCP Server MCP server (jorgearturoyap-debug/metatrader-5-for-chatgpt-desktop). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.