suggest_chord_progression · Orpheus MCP: Risk & Policy

WHAT IT DOES

What suggest_chord_progression does on Orpheus

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

WHY IT NEEDS A POLICY

Why suggest_chord_progression needs a policy

This tool creates new musical data (a chord progression in MIDI form) that can be inserted into a music project. While not destructive and not reading existing data, it actively generates and outputs new creative content. The 'concrete MIDI' component indicates artifact creation rather than pure analysis.

From the tool's definition Tool generates and provides 'concrete MIDI' output, which represents creation of musical data. Combined with the server's context of 'reshaping' music projects, this tool creates new musical content (MIDI data) that would be applied to a REAPER project.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

suggest_chord_progression Rate-limited

suggest_chord_progression 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": {
    "suggest_chord_progression": {
      "limits": [
        {
          "counter": "suggest_chord_progression_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 Orpheus, so you can run agents against it safely.

FAQ

Questions about suggest_chord_progression

What does the suggest_chord_progression tool do? +

A genre-typical diatonic progression as Roman numerals + concrete MIDI. It is categorised as a Write tool in the Orpheus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on suggest_chord_progression? +

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

What risk level is suggest_chord_progression? +

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

Can I rate-limit suggest_chord_progression? +

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

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

suggest_chord_progression is provided by the Orpheus MCP server (mal0ware/orpheus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.