open_nodes · MCP Code Expert System MCP: Risk & Policy

WHAT IT DOES

What open_nodes does on MCP Code Expert System

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

WHY IT NEEDS A POLICY

Why open_nodes needs a policy

An AI agent can call open_nodes faster than any human can review — one bad instruction and it creates or modifies resources in MCP Code Expert System by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

open_nodes Rate-limited

open_nodes 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": {
    "open_nodes": {
      "limits": [
        {
          "counter": "open_nodes_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 MCP Code Expert System, so you can run agents against it safely.

FAQ

Questions about open_nodes

What does the open_nodes tool do? +

Open specific nodes in the knowledge graph by their names. It is categorised as a Write tool in the MCP Code Expert System MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on open_nodes? +

Register the MCP Code Expert System MCP server in PolicyLayer and add a rule for open_nodes: 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 Code Expert System. Nothing to install.

What risk level is open_nodes? +

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

Can I rate-limit open_nodes? +

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

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

open_nodes is provided by the MCP Code Expert System MCP server (tomsiwik/mcp-experts). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.