generate_ui_spec · VibeServe MCP: Risk & Policy

WHAT IT DOES

What generate_ui_spec does on VibeServe

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

WHY IT NEEDS A POLICY

Why generate_ui_spec needs a policy

This tool generates and creates UI specifications based on natural language input. While it performs analysis and validation, the primary action is Write (generating new specification documents/data).

From the tool's definition Tool description states it will "Generate a production-ready UI specification" — this is a create/write operation that produces artifacts (UI specifications).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

generate_ui_spec Rate-limited

generate_ui_spec 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_ui_spec": {
      "limits": [
        {
          "counter": "generate_ui_spec_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 VibeServe, so you can run agents against it safely.

FAQ

Questions about generate_ui_spec

What does the generate_ui_spec tool do? +

Generate a production-ready UI specification with multi-agent critique, WCAG AAA validation, and design system enforcement. It is categorised as a Write tool in the VibeServe 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_ui_spec? +

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

What risk level is generate_ui_spec? +

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

Can I rate-limit generate_ui_spec? +

Yes. Add a rate_limit block to the generate_ui_spec 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_ui_spec completely? +

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

generate_ui_spec is provided by the VibeServe MCP server (ncsound919/vibeserve). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.