Run or list npm scripts from package.json with caching
AI agents invoke nodejs_scripts to trigger actions in MCP DevTools Server. 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.
This tool executes external operations (npm scripts) whose effects depend entirely on script arguments and package.json contents. While listing scripts is read-only, the primary capability is execution, which is the most severe action. npm scripts are a common attack surface and can perform destructive or malicious operations if misused by an AI agent.
From the tool's definition Tool description states "Run or list npm scripts from package.json" — the 'Run' verb indicates execution of arbitrary code.
Documented attack patterns abuse exactly the kind of access nodejs_scripts gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP DevTools Server, and nothing reaches the server without passing your rules. This is the rule we recommend for nodejs_scripts:
{
"version": "1",
"default": "deny",
"tools": {
"nodejs_scripts": {
"limits": [
{
"counter": "nodejs_scripts_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}nodejs_scripts 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.
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Run or list npm scripts from package.json with caching. It is categorised as a Execute tool in the MCP DevTools Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the MCP DevTools Server MCP server in PolicyLayer and add a rule for nodejs_scripts: 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 DevTools Server. Nothing to install.
nodejs_scripts is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the nodejs_scripts 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.
Set action: deny in the PolicyLayer policy for nodejs_scripts. 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.
nodejs_scripts is provided by the MCP DevTools Server MCP server (rshade/mcp-devtools-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP DevTools Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
79 MCP DevTools Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.