draw_circle · CAD- MCP: Risk & Policy

WHAT IT DOES

What draw_circle does on CAD-MCP

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

WHY IT NEEDS A POLICY

Why draw_circle needs a policy

This tool creates/draws a new circle object in the CAD drawing. It is a reversible write operation (the circle can be deleted or undone), with low blast radius as it only adds a geometric shape to the drawing canvas.

From the tool's definition 绘制圆 (draw circle) — creates a circle shape with parameters: center, radius, optional layer, color, and lineweight

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

draw_circle Rate-limited

draw_circle 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": {
    "draw_circle": {
      "limits": [
        {
          "counter": "draw_circle_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 CAD-MCP, so you can run agents against it safely.

FAQ

Questions about draw_circle

What does the draw_circle tool do? +

绘制圆。参数: center, radius, layer?, color?, lineweight?. It is categorised as a Write tool in the CAD-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 draw_circle? +

Register the CAD- MCP server in PolicyLayer and add a rule for draw_circle: 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 CAD-MCP. Nothing to install.

What risk level is draw_circle? +

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

Can I rate-limit draw_circle? +

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

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

draw_circle is provided by the CAD- MCP server (piexl/cad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.