design_content · Pen MCP: Risk & Policy

WHAT IT DOES

What design_content does on Pen

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

WHY IT NEEDS A POLICY

Why design_content needs a policy

The tool creates or modifies content nodes in a design section, which is a reversible data modification operation. There is no indication of deletion, execution of arbitrary code, or financial impact. The 'medium' severity reflects that incorrect use could alter document structure, but changes are reversible. Confidence is 0.8 rather than higher because the description lacks detail about scope and undo mechanisms.

From the tool's definition Populate a section with content nodes—description explicitly indicates creation/modification of design content within a section.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

design_content Rate-limited

design_content 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": {
    "design_content": {
      "limits": [
        {
          "counter": "design_content_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 Pen, so you can run agents against it safely.

FAQ

Questions about design_content

What does the design_content tool do? +

Populate a section with content nodes. Part of the layered design workflow. It is categorised as a Write tool in the Pen MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on design_content? +

Register the Pen MCP server in PolicyLayer and add a rule for design_content: 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 Pen. Nothing to install.

What risk level is design_content? +

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

Can I rate-limit design_content? +

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

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

design_content is provided by the Pen MCP server (@zseven-w/pen-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.