draw_paths · Open Brush MCP Server MCP: Risk & Policy

WHAT IT DOES

What draw_paths does on Open Brush MCP Server

AI agents invoke draw_paths to trigger actions in Open Brush MCP 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.

WHY IT NEEDS A POLICY

Why draw_paths needs a policy

This tool executes an action in external 3D painting software (Open Brush), causing it to render paths. It is not a simple data read or write to a database, but an operation that triggers external software behavior. While reversible in principle (strokes can likely be undone), it is fundamentally an Execute-category action as it drives external application state through the API.

From the tool's definition 'Draws a series of paths at the current brush position' — triggers an external drawing operation in Open Brush via HTTP API

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

draw_paths Rate-limited

draw_paths 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": {
    "draw_paths": {
      "limits": [
        {
          "counter": "draw_paths_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 Open Brush MCP Server, so you can run agents against it safely.

FAQ

Questions about draw_paths

What does the draw_paths tool do? +

Draws a series of paths at the current brush position. It is categorised as a Execute tool in the Open Brush MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on draw_paths? +

Register the Open Brush MCP Server MCP server in PolicyLayer and add a rule for draw_paths: 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 Open Brush MCP Server. Nothing to install.

What risk level is draw_paths? +

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

Can I rate-limit draw_paths? +

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

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

draw_paths is provided by the Open Brush MCP Server MCP server (moz411/openbrush-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.