design_iterate · RC Engine MCP: Risk & Policy

WHAT IT DOES

What design_iterate does on RC Engine

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

WHY IT NEEDS A POLICY

Why design_iterate needs a policy

This tool modifies existing design artifacts (wireframes) by regenerating them based on feedback. It overwrites previous wireframe content, but this is a reversible creative/document modification rather than destructive deletion — prior specs could be reloaded or re-run. It creates/updates design specs, placing it firmly in Write.

From the tool's definition Iterate on existing wireframes based on user feedback... regenerates wireframes for specified screens (or all screens) applying the feedback

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

design_iterate Rate-limited

design_iterate 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_iterate": {
      "limits": [
        {
          "counter": "design_iterate_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 RC Engine, so you can run agents against it safely.

FAQ

Questions about design_iterate

What does the design_iterate tool do? +

Iterate on existing wireframes based on user feedback. Loads the current design spec and regenerates wireframes for specified screens (or all screens) applying the feedback. Maintains design system consistency. Requires ux_design to have been run first. It is categorised as a Write tool in the RC Engine 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_iterate? +

Register the RC Engine MCP server in PolicyLayer and add a rule for design_iterate: 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 RC Engine. Nothing to install.

What risk level is design_iterate? +

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

Can I rate-limit design_iterate? +

Yes. Add a rate_limit block to the design_iterate 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_iterate completely? +

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

design_iterate is provided by the RC Engine MCP server (originalrashmi/rc-engine-product-framework). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.