chart_bar · SVG Canvas MCP: Risk & Policy

WHAT IT DOES

What chart_bar does on SVG Canvas MCP

AI agents use chart_bar 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 chart_bar needs a policy

Creating a chart is a write operation—it generates new SVG content that can be modified or discarded. It does not execute arbitrary code, delete data, or trigger financial transactions. The blast radius of misuse is minimal since it only produces graphical output within the SVG canvas context. Severity is low because charting operations are non-destructive and have limited operational impact.

From the tool's definition Tool name 'chart_bar' and description indicate creation of bar chart graphics. The broader server context shows this is an SVG graphics manipulation tool for 'creation and manipulation of professional-grade SVG graphics'.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

chart_bar Rate-limited

chart_bar 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": {
    "chart_bar": {
      "limits": [
        {
          "counter": "chart_bar_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 chart_bar

What does the chart_bar tool do? +

막대 차트를 생성합니다. 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 chart_bar? +

Register the SVG Canvas MCP server in PolicyLayer and add a rule for chart_bar: 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 chart_bar? +

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

Can I rate-limit chart_bar? +

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

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

chart_bar 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.