create_flowchart · Diagram MCP: Risk & Policy

WHAT IT DOES

What create_flowchart does on DiagramMCP

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

WHY IT NEEDS A POLICY

Why create_flowchart needs a policy

The tool name 'create_flowchart' strongly implies it creates/generates a flowchart diagram. Based on the server's description of generating diagrams using Mermaid syntax, this is a Write operation that produces a new diagram artifact. The description is empty, which lowers confidence, but the sibling tools (create_architecture_diagram, create_class_diagram, etc.) follow a consistent pattern.

From the tool's definition Tool name 'create_flowchart' and server context describing dynamic generation of diagrams using Mermaid syntax.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_flowchart Rate-limited

create_flowchart 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": {
    "create_flowchart": {
      "limits": [
        {
          "counter": "create_flowchart_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 DiagramMCP, so you can run agents against it safely.

FAQ

Questions about create_flowchart

What does the create_flowchart tool do? +

create_flowchart. It is categorised as a Write tool in the DiagramMCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_flowchart? +

Register the Diagram MCP server in PolicyLayer and add a rule for create_flowchart: 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 DiagramMCP. Nothing to install.

What risk level is create_flowchart? +

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

Can I rate-limit create_flowchart? +

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

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

create_flowchart is provided by the Diagram MCP server (lelondelonmelon/diagrammcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.