farmbot_unlock · Farmbot Agent MCP: Risk & Policy

WHAT IT DOES

What farmbot_unlock does on Farmbot Agent

AI agents invoke farmbot_unlock to trigger actions in Farmbot Agent. 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 farmbot_unlock needs a policy

This tool triggers a physical hardware state change — re-enabling a device that was locked due to an emergency stop. It doesn't merely read or write data; it executes an operational command that restores full movement capability to physical hardware. Misuse could allow the robot to resume movement prematurely in an unsafe situation, posing physical risk.

From the tool's definition Unlock the FarmBot device after an emergency stop... the device is locked and will not respond to movement commands. Call this to unlock and resume normal operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

farmbot_unlock Rate-limited

farmbot_unlock 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": {
    "farmbot_unlock": {
      "limits": [
        {
          "counter": "farmbot_unlock_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 Farmbot Agent, so you can run agents against it safely.

FAQ

Questions about farmbot_unlock

What does the farmbot_unlock tool do? +

Unlock the FarmBot device after an emergency stop. After calling farmbot_emergency_stop, the device is locked and will not respond to movement commands. Call this to unlock and resume normal operation. It is categorised as a Execute tool in the Farmbot Agent MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on farmbot_unlock? +

Register the Farmbot Agent MCP server in PolicyLayer and add a rule for farmbot_unlock: 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 Farmbot Agent. Nothing to install.

What risk level is farmbot_unlock? +

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

Can I rate-limit farmbot_unlock? +

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

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

farmbot_unlock is provided by the Farmbot Agent MCP server (kieranklaassen/farmbot-agent-cli-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.