symbol_select · MetaTrader 5 MCP Server MCP: Risk & Policy

WHAT IT DOES

What symbol_select does on MetaTrader 5 MCP Server

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

WHY IT NEEDS A POLICY

Why symbol_select needs a policy

In MetaTrader 5, 'symbol_select' adds or removes a symbol from the Market Watch window, which is a reversible configuration change. It does not place trades or delete data, so Write is the most appropriate category. Confidence is lowered due to the empty description.

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

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

symbol_select Rate-limited

symbol_select 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": {
    "symbol_select": {
      "limits": [
        {
          "counter": "symbol_select_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 Server, so you can run agents against it safely.

FAQ

Questions about symbol_select

What does the symbol_select tool do? +

symbol_select. It is categorised as a Write tool in the MetaTrader 5 MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on symbol_select? +

Register the MetaTrader 5 MCP Server MCP server in PolicyLayer and add a rule for symbol_select: 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 symbol_select? +

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

Can I rate-limit symbol_select? +

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

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

symbol_select is provided by the MetaTrader 5 MCP Server MCP server (sameerasulakshana/mcpmt5). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.