change_time_signature · Musescore MCP: Risk & Policy

WHAT IT DOES

What change_time_signature does on Musescore

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

WHY IT NEEDS A POLICY

Why change_time_signature needs a policy

The tool modifies musical metadata (time signature) in a MuseScore file, which is a reversible change. This qualifies as Write rather than Execute (no code/command execution), Destructive (change is reversible), or other categories. Severity is medium because incorrect time signature changes could corrupt musical intent or require manual correction, but the change is undoable.

From the tool's definition Tool name 'change_time_signature' indicates modification of musical notation properties. Server description emphasizes 'edit' capability and sibling tools include 'change_tempo' and 'apply_style' which are write operations on MuseScore files.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

change_time_signature Rate-limited

change_time_signature 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": {
    "change_time_signature": {
      "limits": [
        {
          "counter": "change_time_signature_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Musescore, so you can run agents against it safely.

FAQ

Questions about change_time_signature

What does the change_time_signature tool do? +

change_time_signature. It is categorised as a Write tool in the Musescore MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on change_time_signature? +

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

What risk level is change_time_signature? +

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

Can I rate-limit change_time_signature? +

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

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

change_time_signature is provided by the Musescore MCP server (strongbeen04/musescore-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.