vm_list

THE RISK

Low Risk

Why vm_list needs a policy

This tool retrieves information about VM instances without creating, modifying, deleting, or executing any actions. It is a simple listing/enumeration operation with minimal risk unless the VM inventory itself is highly sensitive, but listing is fundamentally a read-only operation.

From the tool's definition Tool name 'vm_list' and description 'List all VM instances' indicate a query/retrieval operation with no modification or execution of resources.

Documented attack patterns abuse exactly the kind of access vm_list gives an agent:

POLICY

How to control vm_list

PolicyLayer is an MCP gateway — it sits between your AI agents and tmux-claude MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for vm_list:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "vm_list": {}
  }
}

vm_list is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register tmux-claude MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More tmux-claude MCP Server tools

Destructive terminate Terminate a Claude instance and optionally its children Destructive vm_terminate Terminate a VM instance (permanent destruction) Execute executeParallel Execute multiple tasks in parallel using Specialist instances (Manager only) Execute restart Restart a dead instance using --continue flag Execute vm_start Start a stopped VM instance Execute vm_stop Stop a running VM instance Execute distributeWork Distribute tasks across multiple Managers (Executive only) Execute enhancedSend Send a message with queuing and guaranteed delivery

All 26 tmux-claude MCP Server tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about vm_list

What does the vm_list tool do? +

List all VM instances. It is categorised as a Read tool in the tmux-claude MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on vm_list? +

Register the tmux-claude MCP Server MCP server in PolicyLayer and add a rule for vm_list: 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 tmux-claude MCP Server. Nothing to install.

What risk level is vm_list? +

vm_list is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit vm_list? +

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

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

vm_list is provided by the tmux-claude MCP Server MCP server (michael-abdo/tmux-claude-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every tmux-claude MCP Server tool call.

Start from tmux-claude MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →