bim_import_ifc · FreeCAD MCP: Risk & Policy

WHAT IT DOES

What bim_import_ifc does on FreeCAD MCP

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

WHY IT NEEDS A POLICY

Why bim_import_ifc needs a policy

bim_import_ifc loads and integrates external IFC files into a FreeCAD BIM project, which creates or substantially modifies the model data within the application. This is a reversible Write operation—the imported data can be undone or removed. It is not Read (import has side effects beyond retrieval), not Execute (no arbitrary code/command execution implied), not Destructive (reversible), and not Financial.

From the tool's definition Tool name is 'bim_import_ifc' which imports IFC (Industry Foundation Classes) building information models.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

bim_import_ifc Rate-limited

bim_import_ifc 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": {
    "bim_import_ifc": {
      "limits": [
        {
          "counter": "bim_import_ifc_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 FreeCAD MCP, so you can run agents against it safely.

FAQ

Questions about bim_import_ifc

What does the bim_import_ifc tool do? +

bim_import_ifc. It is categorised as a Write tool in the FreeCAD MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on bim_import_ifc? +

Register the FreeCAD MCP server in PolicyLayer and add a rule for bim_import_ifc: 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 FreeCAD MCP. Nothing to install.

What risk level is bim_import_ifc? +

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

Can I rate-limit bim_import_ifc? +

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

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

bim_import_ifc is provided by the FreeCAD MCP server (sandraschi/freecad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.