execute-command · Ryan's Tmux MCP Server MCP: Risk & Policy

WHAT IT DOES

What execute-command does on Ryan's Tmux MCP Server

AI agents invoke execute-command to trigger actions in Ryan's Tmux MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why execute-command needs a policy

This tool sends arbitrary commands to tmux panes, allowing execution of shell commands whose effects cannot be predicted and are entirely dependent on the arguments provided. An AI agent given access could execute destructive commands (rm -rf), financial transactions, or other arbitrary operations.

From the tool's definition Tool description states 'Send keys/command to a tmux pane' and name is 'execute-command'. This provides arbitrary command execution within tmux sessions, which can trigger external operations with effects dependent on the command arguments.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

execute-command Rate-limited

execute-command stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "execute-command": {
      "limits": [
        {
          "counter": "execute-command_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about execute-command

What does the execute-command tool do? +

Send keys/command to a tmux pane. It is categorised as a Execute tool in the Ryan's Tmux MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on execute-command? +

Register the Ryan's Tmux MCP Server MCP server in PolicyLayer and add a rule for execute-command: 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 Ryan's Tmux MCP Server. Nothing to install.

What risk level is execute-command? +

execute-command is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit execute-command? +

Yes. Add a rate_limit block to the execute-command 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 execute-command completely? +

Set action: deny in the PolicyLayer policy for execute-command. 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 execute-command? +

execute-command is provided by the Ryan's Tmux MCP Server MCP server (ryancnelson/ryan-tmux-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.