export_diagram_as_image · StarUML MCP Server MCP

WHAT IT DOES

What export_diagram_as_image does on StarUML MCP Server

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

WHY IT NEEDS A POLICY

Why export_diagram_as_image needs a policy

This tool reads an existing diagram from StarUML and converts it to an image format for export. While it produces a new artifact (the PNG file), this is a reversible operation with no destructive side effects, no code execution, no financial impact, and no uncontrollable external effects. It fits the Write category as it generates/creates exportable data.

From the tool's definition Tool exports/generates diagram as image file (returns base64-encoded PNG). The description states '导出指定图表为图片' (export specified diagram as image), which is a data generation and retrieval operation that produces an output file artifact.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

export_diagram_as_image Rate-limited

export_diagram_as_image 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": {
    "export_diagram_as_image": {
      "limits": [
        {
          "counter": "export_diagram_as_image_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 StarUML MCP Server, so you can run agents against it safely.

FAQ

Questions about export_diagram_as_image

What does the export_diagram_as_image tool do? +

导出指定图表为图片（返回 base64 编码的 PNG）。. It is categorised as a Write tool in the StarUML 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 export_diagram_as_image? +

Register the StarUML MCP Server MCP server in PolicyLayer and add a rule for export_diagram_as_image: 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 StarUML MCP Server. Nothing to install.

What risk level is export_diagram_as_image? +

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

Can I rate-limit export_diagram_as_image? +

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

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

export_diagram_as_image is provided by the StarUML MCP Server MCP server (stonesho/staruml_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.