cfd_build_case · FreeCAD MCP: Risk & Policy

WHAT IT DOES

What cfd_build_case does on FreeCAD MCP

AI agents invoke cfd_build_case to trigger actions in FreeCAD MCP. 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 cfd_build_case needs a policy

CFD (Computational Fluid Dynamics) case building is an Execute action—it triggers complex external computation whose effects depend on configuration parameters. While not directly destructive, it commits computational resources and produces outputs that could affect downstream design decisions.

From the tool's definition Tool name 'cfd_build_case' with 'cfd' prefix indicates fluid dynamics simulation setup. Context shows this server handles 'fluid simulation' operations. The 'build' action suggests configuring and preparing a computational case.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cfd_build_case Rate-limited

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

FAQ

Questions about cfd_build_case

What does the cfd_build_case tool do? +

cfd_build_case. It is categorised as a Execute tool in the FreeCAD MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cfd_build_case? +

Register the FreeCAD MCP server in PolicyLayer and add a rule for cfd_build_case: 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 cfd_build_case? +

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

Can I rate-limit cfd_build_case? +

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

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

cfd_build_case 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.