generate_vcv · Synthlab MCP: Risk & Policy

WHAT IT DOES

What generate_vcv does on Synthlab

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

WHY IT NEEDS A POLICY

Why generate_vcv needs a policy

This tool creates a new patch file (.vcv format) based on input specifications. This is a Write operation as it produces new data artifacts that can be modified or deleted later. Severity is medium because misuse could create unintended audio synthesis configurations, but the effects are reversible—files can be deleted or overwritten. It does not execute arbitrary code, delete data irreversibly, or move funds.

From the tool's definition Tool description states it generates a VCV Rack .vcv patch file from a JSON specification. The verb 'generate' and 'create' a file output indicates data creation/modification. The sibling tool 'create_rack' reinforces this is a creation operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

generate_vcv Rate-limited

generate_vcv 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_vcv": {
      "limits": [
        {
          "counter": "generate_vcv_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 Synthlab, so you can run agents against it safely.

FAQ

Questions about generate_vcv

What does the generate_vcv tool do? +

Generate a VCV Rack .vcv patch file from a JSON specification of modules and cables. It is categorised as a Write tool in the Synthlab 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_vcv? +

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

What risk level is generate_vcv? +

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

Can I rate-limit generate_vcv? +

Yes. Add a rate_limit block to the generate_vcv 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_vcv completely? +

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

generate_vcv is provided by the Synthlab MCP server (j0kz/synthlab-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.