export_function_slice · JS Reverse MCP: Risk & Policy

WHAT IT DOES

What export_function_slice does on JS Reverse MCP

AI agents invoke export_function_slice to trigger actions in JS Reverse MCP. 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 export_function_slice needs a policy

The tool builds and executes a function slice with a Node environment shim, indicating it runs or constructs executable code artifacts. The 'Node env shim' suggests it sets up a runtime environment, placing this in the Execute category.

From the tool's definition Build a minimal function slice draft with direct helper dependencies and a Node env shim

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

export_function_slice Rate-limited

export_function_slice 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": {
    "export_function_slice": {
      "limits": [
        {
          "counter": "export_function_slice_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 JS Reverse MCP, so you can run agents against it safely.

FAQ

Questions about export_function_slice

What does the export_function_slice tool do? +

Build a minimal function slice draft with direct helper dependencies and a Node env shim. It is categorised as a Execute tool in the JS Reverse MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on export_function_slice? +

Register the JS Reverse MCP server in PolicyLayer and add a rule for export_function_slice: 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 JS Reverse MCP. Nothing to install.

What risk level is export_function_slice? +

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

Can I rate-limit export_function_slice? +

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

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

export_function_slice is provided by the JS Reverse MCP server (noone-hub/jsreverser-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.