modify_position · MetaTrader 5 MCP: Risk & Policy

WHAT IT DOES

What modify_position does on MetaTrader 5 MCP

AI agents use modify_position to create or update resources in MetaTrader 5 MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MetaTrader 5 MCP environment.

WHY IT NEEDS A POLICY

Why modify_position needs a policy

This tool modifies parameters on an existing open trading position (stop loss and take profit levels). While it doesn't directly move money or place/close trades, changing these levels on a live financial position can significantly affect trade outcomes and risk exposure.

From the tool's definition Update the stop loss and/or take profit on an open position

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

modify_position Rate-limited

modify_position stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "modify_position": {
      "limits": [
        {
          "counter": "modify_position_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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, so you can run agents against it safely.

FAQ

Questions about modify_position

What does the modify_position tool do? +

Update the stop loss and/or take profit on an open position. It is categorised as a Write tool in the MetaTrader 5 MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on modify_position? +

Register the MetaTrader 5 MCP server in PolicyLayer and add a rule for modify_position: 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. Nothing to install.

What risk level is modify_position? +

modify_position is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit modify_position? +

Yes. Add a rate_limit block to the modify_position 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 modify_position completely? +

Set action: deny in the PolicyLayer policy for modify_position. 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 modify_position? +

modify_position is provided by the MetaTrader 5 MCP server (rpieterse/mcp-studio-mt5-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.