draw_text · CAD- MCP: Risk & Policy

WHAT IT DOES

What draw_text does on CAD-MCP

AI agents use draw_text 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_text needs a policy

The tool creates new text elements in a CAD drawing, which modifies the design state reversibly. While it doesn't execute arbitrary code or delete data, it does persistently alter the CAD document. This is a Write operation because the changes are reversible (text can be edited or removed) and non-destructive.

From the tool's definition Tool name 'draw_text' with description indicating it 'adds text' (添加文本) to CAD drawings with parameters for position, text content, and optional formatting. This is a creation operation on design data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

draw_text Rate-limited

draw_text 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_text": {
      "limits": [
        {
          "counter": "draw_text_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_text

What does the draw_text tool do? +

添加文本。参数: position, text, height?, rotation?, layer?, color?. 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_text? +

Register the CAD- MCP server in PolicyLayer and add a rule for draw_text: 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_text? +

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

Can I rate-limit draw_text? +

Yes. Add a rate_limit block to the draw_text 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_text completely? +

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

draw_text 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.