farmbot_add_tool · Farmbot Agent MCP: Risk & Policy

WHAT IT DOES

What farmbot_add_tool does on Farmbot Agent

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

WHY IT NEEDS A POLICY

Why farmbot_add_tool needs a policy

This tool creates new tool records in the FarmBot system, which is a reversible write operation. While the system controls physical hardware, registering a tool is merely a data creation step with no direct physical effects. The tool itself does not execute hardware commands, move equipment, or trigger irreversible changes—those are separate tools (farmbot_calibrate, farmbot_emergency_stop, etc.).

From the tool's definition Tool description explicitly states 'Register a new tool' and references creating and assigning tools to slots, which are reversible configuration changes. No destructive, financial, or code execution operations are involved.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

farmbot_add_tool Rate-limited

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

FAQ

Questions about farmbot_add_tool

What does the farmbot_add_tool tool do? +

Register a new tool (Watering Nozzle, Seeder, Soil Sensor, Rotary Tool, etc). After creating, assign it to a slot via farmbot_add_point with pointer_type=ToolSlot referencing the new tool_id. It is categorised as a Write tool in the Farmbot Agent MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on farmbot_add_tool? +

Register the Farmbot Agent MCP server in PolicyLayer and add a rule for farmbot_add_tool: 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_add_tool? +

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

Can I rate-limit farmbot_add_tool? +

Yes. Add a rate_limit block to the farmbot_add_tool 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_add_tool completely? +

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

farmbot_add_tool 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.