reload_metro · MCP Connect MCP: Risk & Policy

WHAT IT DOES

What reload_metro does on MCP Connect

AI agents invoke reload_metro to trigger actions in MCP Connect. 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 reload_metro needs a policy

reload_metro performs an Execute action by triggering an external operation (Metro bundler reload) rather than simply reading data (Read) or making reversible modifications (Write). The tool invokes an external process with side effects on the Metro development server. While this is reversible (unlike Destructive actions), it qualifies as Execute because it runs an external command/operation.

From the tool's definition Tool description explicitly states 'Trigger reload in Metro bundler', which is an external operation that initiates a process. Metro is the JavaScript bundler used by React Native.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

reload_metro Rate-limited

reload_metro 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": {
    "reload_metro": {
      "limits": [
        {
          "counter": "reload_metro_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 MCP Connect, so you can run agents against it safely.

FAQ

Questions about reload_metro

What does the reload_metro tool do? +

Trigger reload in Metro bundler. It is categorised as a Execute tool in the MCP Connect MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on reload_metro? +

Register the MCP Connect MCP server in PolicyLayer and add a rule for reload_metro: 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 MCP Connect. Nothing to install.

What risk level is reload_metro? +

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

Can I rate-limit reload_metro? +

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

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

reload_metro is provided by the MCP Connect MCP server (plaintest/mcp-connect). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.