generate_variants · Stitch- MCP: Risk & Policy

WHAT IT DOES

What generate_variants does on Stitch-MCP

AI agents use generate_variants 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 generate_variants needs a policy

Despite the empty description, the name 'generate_variants' and its context within a UI design tool suite indicate this creates or generates design variants (likely screen designs or design system variations). This is a Write operation—it produces new design content.

From the tool's definition Tool name 'generate_variants' in a design system context; sibling tools include 'generate_screen_from_text', 'edit_screens', and 'create_design_system' which are clearly generative/creative operations that produce new design artifacts.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

generate_variants Rate-limited

generate_variants 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": {
    "generate_variants": {
      "limits": [
        {
          "counter": "generate_variants_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 generate_variants

What does the generate_variants tool do? +

generate_variants. 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 generate_variants? +

Register the Stitch- MCP server in PolicyLayer and add a rule for generate_variants: 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 generate_variants? +

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

Can I rate-limit generate_variants? +

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

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

generate_variants 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.