Medium Risk

add_sketch_ellipse

Add an ellipse to a sketch. Args: sketch_name: Name of the sketch to add ellipse to. center_x: X coordinate of center. center_y: Y coordinate of center. major_radius: Semi-major axis radius. minor_radius: Semi-minor axis radius. doc_name: Document containing the sketch. Uses active document if No...

How to control add_sketch_ellipse ↓

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

Medium Risk

This tool creates (writes) new geometric data to a sketch in FreeCAD. It is reversible because FreeCAD sketches support undo operations and element deletion, unlike destructive operations. The severity is medium because misuse could corrupt a design project, but the scope is limited to a single sketch element and can be easily undone.

From the tool's definition The tool 'add_sketch_ellipse' creates a new ellipse geometry element in a sketch by taking parameters for center coordinates, major and minor radii.

Documented attack patterns abuse exactly the kind of access add_sketch_ellipse gives an agent:

PolicyLayer is an MCP gateway — it sits between your AI agents and FreeCAD Robust MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_sketch_ellipse:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_sketch_ellipse": {
      "limits": [
        {
          "counter": "add_sketch_ellipse_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

add_sketch_ellipse 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.

  1. Create a free account and register FreeCAD Robust MCP Server — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

Free to start. No card required.

Go deeper

What does the add_sketch_ellipse tool do? +

Add an ellipse to a sketch. Args: sketch_name: Name of the sketch to add ellipse to. center_x: X coordinate of center. center_y: Y coordinate of center. major_radius: Semi-major axis radius. minor_radius: Semi-minor axis radius. doc_name: Document containing the sketch. Uses active document if None. Returns: Dictionary with geometry info: - geometry_index: Index of the added ellipse - geometry_count: Total geometry elements. It is categorised as a Write tool in the FreeCAD Robust MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_sketch_ellipse? +

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

What risk level is add_sketch_ellipse? +

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

Can I rate-limit add_sketch_ellipse? +

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

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

add_sketch_ellipse is provided by the FreeCAD Robust MCP Server MCP server (spkane/freecad-addon-robust-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every FreeCAD Robust MCP Server tool call.

Deterministic rules across all 152 FreeCAD Robust MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

152 FreeCAD Robust MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

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