# write_coil

A write tool on the Pypi:labmcp Alicat MCP server.

Agent View of the PolicyLayer registry record for `write_coil`. HTML page: https://policylayer.com/tools/lab-instrument-mcps/write-coil

## Facts

- Tool: `write_coil`
- Server: Pypi:labmcp Alicat (`pypi:labmcp-alicat`) — https://policylayer.com/tools/lab-instrument-mcps.md
- Install: `npx -y pypi:labmcp-alicat`
- Homepage: https://github.com/K-Dense-AI/lab-instrument-mcps
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "write_coil",
    "arguments": {}
  }
}
```

## Why write_coil is rated Medium

Modbus coils control physical industrial equipment and processes. Writing to coils can change the state of connected devices (pumps, motors, valves, etc.). While not destructive in the data-deletion sense, misuse could cause unintended physical actions. The empty description lowers confidence slightly, but the name and context are sufficiently clear.

From the tool's own definition: "Tool name is 'write_coil' and is part of the Modbus protocol toolset. Modbus coils are binary output registers that control physical devices. The 'write_' prefix indicates a modification operation."

## Use case

AI agents use write_coil to create or update resources in Pypi:labmcp Alicat, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Pypi:labmcp Alicat environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Pypi:labmcp Alicat:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "write_coil": {
      "limits": [
        {
          "counter": "write_coil_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Pypi:labmcp Alicat (241)

- `clear_calibration` — Destructive — https://policylayer.com/tools/lab-instrument-mcps/clear-calibration.md
- `clear_protection_trip` — Destructive — https://policylayer.com/tools/lab-instrument-mcps/clear-protection-trip.md
- `clear_results` — Destructive — https://policylayer.com/tools/lab-instrument-mcps/clear-results.md
- `stop_run` — Destructive — https://policylayer.com/tools/lab-instrument-mcps/stop-run.md
- `abort_measurement` — Execute — https://policylayer.com/tools/lab-instrument-mcps/abort-measurement.md
- `acquire_spectrum` — Execute — https://policylayer.com/tools/lab-instrument-mcps/acquire-spectrum.md
- `acquire_time_lapse` — Execute — https://policylayer.com/tools/lab-instrument-mcps/acquire-time-lapse.md
- `acquire_z_stack` — Execute — https://policylayer.com/tools/lab-instrument-mcps/acquire-z-stack.md
- `all_heaters_off` — Execute — https://policylayer.com/tools/lab-instrument-mcps/all-heaters-off.md
- `all_outputs_off` — Execute — https://policylayer.com/tools/lab-instrument-mcps/all-outputs-off.md
- `aspirate_ul` — Execute — https://policylayer.com/tools/lab-instrument-mcps/aspirate-ul.md
- `auto_phase` — Execute — https://policylayer.com/tools/lab-instrument-mcps/auto-phase.md
- `auto_range` — Execute — https://policylayer.com/tools/lab-instrument-mcps/auto-range.md
- `autofocus` — Execute — https://policylayer.com/tools/lab-instrument-mcps/autofocus.md
- `autoscale` — Execute — https://policylayer.com/tools/lab-instrument-mcps/autoscale.md
- `calibrate` — Execute — https://policylayer.com/tools/lab-instrument-mcps/calibrate.md
- `call_command` — Execute — https://policylayer.com/tools/lab-instrument-mcps/call-command.md
- `cancel_command` — Execute — https://policylayer.com/tools/lab-instrument-mcps/cancel-command.md
- `close_shutter` — Execute — https://policylayer.com/tools/lab-instrument-mcps/close-shutter.md
- `configure_board` — Execute — https://policylayer.com/tools/lab-instrument-mcps/configure-board.md
- `deactivate_modules` — Execute — https://policylayer.com/tools/lab-instrument-mcps/deactivate-modules.md
- `device_clear` — Execute — https://policylayer.com/tools/lab-instrument-mcps/device-clear.md
- `disable_watchdog` — Execute — https://policylayer.com/tools/lab-instrument-mcps/disable-watchdog.md
- `dispense_ul` — Execute — https://policylayer.com/tools/lab-instrument-mcps/dispense-ul.md
- `enable_watchdog` — Execute — https://policylayer.com/tools/lab-instrument-mcps/enable-watchdog.md
- `force_trigger` — Execute — https://policylayer.com/tools/lab-instrument-mcps/force-trigger.md
- `frequency_sweep` — Execute — https://policylayer.com/tools/lab-instrument-mcps/frequency-sweep.md
- `hold_valve` — Execute — https://policylayer.com/tools/lab-instrument-mcps/hold-valve.md
- `home_robot` — Execute — https://policylayer.com/tools/lab-instrument-mcps/home-robot.md
- `infuse` — Execute — https://policylayer.com/tools/lab-instrument-mcps/infuse.md
- …and 211 more: https://policylayer.com/tools/lab-instrument-mcps.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=lab-instrument-mcps · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/lab-instrument-mcps