slice_stl · MCP 3D Printer Server MCP: Risk & Policy

WHAT IT DOES

What slice_stl does on MCP 3D Printer Server

AI agents invoke slice_stl to trigger actions in MCP 3D Printer 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 slice_stl needs a policy

Slicing is a computational execution step that transforms a 3D model into machine control code (G-code). While it doesn't directly send commands to the printer, it produces executable instructions for physical hardware. Combined with sibling tools like 'process_and_print_stl', misuse could trigger unattended prints, waste materials, or cause hardware damage.

From the tool's definition 'Slice an STL file to generate G-code' — slicing converts an STL into G-code instructions that directly control physical 3D printer hardware movements, temperatures, and extrusion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

slice_stl Rate-limited

slice_stl 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": {
    "slice_stl": {
      "limits": [
        {
          "counter": "slice_stl_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 MCP 3D Printer Server, so you can run agents against it safely.

FAQ

Questions about slice_stl

What does the slice_stl tool do? +

Slice an STL file to generate G-code. It is categorised as a Execute tool in the MCP 3D Printer 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 slice_stl? +

Register the MCP 3D Printer Server MCP server in PolicyLayer and add a rule for slice_stl: 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 3D Printer Server. Nothing to install.

What risk level is slice_stl? +

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

Can I rate-limit slice_stl? +

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

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

slice_stl is provided by the MCP 3D Printer Server MCP server (mcpflow/dmontgomery40_mcp-3d-printer-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.