// MCP TOOL REFERENCE

Medium Risk

acknowledge-alarms

ServerWinCC Unified MCP Server
CategoryWrite

WHAT IT DOES

What acknowledge-alarms does on WinCC Unified MCP Server

AI agents use acknowledge-alarms to create or update resources in WinCC Unified MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your WinCC Unified MCP Server environment.

THE RISK

Medium Risk

Why acknowledge-alarms needs a policy

Acknowledging alarms in a SCADA/industrial control system is a Write operation — it modifies the state of alarms (from unacknowledged to acknowledged) in a reversible/stateful way.

From the tool's definition Acknowledge one or more alarms... all instances of the given alarm will be acknowledged

Documented attack patterns abuse exactly the kind of access acknowledge-alarms gives an agent:

POLICY

How to control acknowledge-alarms

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "acknowledge-alarms": {
      "limits": [
        {
          "counter": "acknowledge-alarms_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

acknowledge-alarms 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.

Create a free account and register WinCC Unified 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.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More WinCC Unified MCP Server tools

Write reset-alarms Reset one or more alarms. Each alarm identifier must have the name of the configured al Write write-tag-values Updates tags, based on the provided TagValueInput list. If a TagValueInput does not def Read browse-objects Queries tags, elements, types, alarms, logging tags and basically anything that has a conf Read get-active-alarms Query active alarms from the provided systems. The filterString parameter must be a val Read get-logged-alarms Query logged alarms from the storage system. The filterString parameter must be a valid Read get-logged-tag-values Queries logged tag values from the database. Names is a mandatory parameter, each name Read get-tag-values Queries tag values from WinCC Unified. Based on the provided names list. If directRead is Other login-user Logs a user in to WinCC Unified using username and password. Stores the session token

All 9 WinCC Unified MCP Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about acknowledge-alarms

What does the acknowledge-alarms tool do? +

Acknowledge one or more alarms. Each alarm identifier must have the name of the configured alarm, and optionally an instanceID, which identifies one active instance of the configured alarm. If the instanceID is 0 or not provided, all instances of the given alarm will be acknowledged. If an alarm requires single acknowledgement, only one item can be provided at a time, otherwise the request will be rejected. Errors: 0 - Success 2 - Cannot resolve provided name 304 - Invalid object state 305 - The alarm cannot be read / acknowledged / reset in current state x - Alarm instance does not exist (where x is the instanceID or an indicator for the alarm name if no instanceID was provided). It is categorised as a Write tool in the WinCC Unified MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on acknowledge-alarms? +

Register the WinCC Unified MCP Server MCP server in PolicyLayer and add a rule for acknowledge-alarms: 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 WinCC Unified MCP Server. Nothing to install.

What risk level is acknowledge-alarms? +

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

Can I rate-limit acknowledge-alarms? +

Yes. Add a rate_limit block to the acknowledge-alarms 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 acknowledge-alarms completely? +

Set action: deny in the PolicyLayer policy for acknowledge-alarms. 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 acknowledge-alarms? +

acknowledge-alarms is provided by the WinCC Unified MCP Server MCP server (vogler75/winccua-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.