run_python_script · MCPHub MCP: Risk & Policy

WHAT IT DOES

What run_python_script does on MCPHub

AI agents invoke run_python_script to trigger actions in MCPHub. 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 run_python_script needs a policy

Running Python scripts via an agent can execute arbitrary code with the privileges of the MCP server process, including system calls, file operations, network requests, and access to the sibling tools' capabilities. This represents the highest blast radius for uncontrolled code execution. Empty description lowers confidence from 0.98 to 0.95, but the name is definitive.

From the tool's definition Tool name 'run_python_script' indicates execution of arbitrary Python code. Description is empty but the name unambiguously denotes code execution.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

run_python_script Rate-limited

run_python_script 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": {
    "run_python_script": {
      "limits": [
        {
          "counter": "run_python_script_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 MCPHub, so you can run agents against it safely.

FAQ

Questions about run_python_script

What does the run_python_script tool do? +

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

How do I enforce a policy on run_python_script? +

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

What risk level is run_python_script? +

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

Can I rate-limit run_python_script? +

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

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

run_python_script is provided by the MCPHub MCP server (jayden-dong/mcphub). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.