apply_design_system · Stitch- MCP: Risk & Policy

WHAT IT DOES

What apply_design_system does on Stitch-MCP

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

WHY IT NEEDS A POLICY

Why apply_design_system needs a policy

Without explicit description, classification relies on naming convention and server context. 'Apply' indicates a reversible modification operation. The tool likely updates design system associations or properties in design artifacts, making it a Write operation rather than Read (which would be 'get_' or 'list_') or Execute (which would trigger independent external actions).

From the tool's definition Tool name 'apply_design_system' with no description. Context indicates it operates within Google Stitch's design system, which manages UI/design artifacts.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

apply_design_system Rate-limited

apply_design_system 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": {
    "apply_design_system": {
      "limits": [
        {
          "counter": "apply_design_system_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 Stitch-MCP, so you can run agents against it safely.

FAQ

Questions about apply_design_system

What does the apply_design_system tool do? +

apply_design_system. It is categorised as a Write tool in the Stitch-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 apply_design_system? +

Register the Stitch- MCP server in PolicyLayer and add a rule for apply_design_system: 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 Stitch-MCP. Nothing to install.

What risk level is apply_design_system? +

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

Can I rate-limit apply_design_system? +

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

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

apply_design_system is provided by the Stitch- MCP server (samueljayasingh/stitchmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.