draw_polyline · SVG Canvas MCP: Risk & Policy

WHAT IT DOES

What draw_polyline does on SVG Canvas MCP

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

WHY IT NEEDS A POLICY

Why draw_polyline needs a policy

This tool creates visual elements (polylines) on the canvas, which is a reversible write operation. It does not execute arbitrary code, delete data, or cause financial transactions. The blast radius is minimal—worst case, unwanted polylines are drawn but can be undone/removed. Severity is low because SVG drawing operations have limited negative impact.

From the tool's definition draw_polyline creates/modifies graphics content by drawing connected lines on an SVG canvas. The tool description translates from Korean as 'draws a line connecting multiple points', which is a creation operation that modifies the SVG document state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

draw_polyline Rate-limited

draw_polyline 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_polyline": {
      "limits": [
        {
          "counter": "draw_polyline_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 SVG Canvas MCP, so you can run agents against it safely.

FAQ

Questions about draw_polyline

What does the draw_polyline tool do? +

여러 점을 연결하는 선을 그립니다. It is categorised as a Write tool in the SVG Canvas 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_polyline? +

Register the SVG Canvas MCP server in PolicyLayer and add a rule for draw_polyline: 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 SVG Canvas MCP. Nothing to install.

What risk level is draw_polyline? +

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

Can I rate-limit draw_polyline? +

Yes. Add a rate_limit block to the draw_polyline 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_polyline completely? +

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

draw_polyline is provided by the SVG Canvas MCP server (kim62210/svg-canvas-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.