extend_stl_base · Bambu Printer MCP: Risk & Policy

WHAT IT DOES

What extend_stl_base does on Bambu Printer

AI agents use extend_stl_base to create or update resources in Bambu Printer — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Bambu Printer environment.

WHY IT NEEDS A POLICY

Why extend_stl_base needs a policy

The tool performs a computational modification to a 3D model file, which is reversible and non-destructive. While it changes file content, it does not delete data (which would be Destructive) or execute arbitrary code (which would be Execute). A misclassification as Execute would overstate the risk since the operation is bounded to a single, well-defined geometric transformation.

From the tool's definition Tool modifies STL file by extending its base by a specified amount. This is a reversible transformation of 3D model data (the sibling tool blender_mcp_edit_model confirms the server supports model manipulation).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

extend_stl_base Rate-limited

extend_stl_base 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": {
    "extend_stl_base": {
      "limits": [
        {
          "counter": "extend_stl_base_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 Bambu Printer, so you can run agents against it safely.

FAQ

Questions about extend_stl_base

What does the extend_stl_base tool do? +

Extend the base of an STL file by a specified amount. It is categorised as a Write tool in the Bambu Printer MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on extend_stl_base? +

Register the Bambu Printer MCP server in PolicyLayer and add a rule for extend_stl_base: 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 Bambu Printer. Nothing to install.

What risk level is extend_stl_base? +

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

Can I rate-limit extend_stl_base? +

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

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

extend_stl_base is provided by the Bambu Printer MCP server (rowbotik/bambu-printer-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.