list_watchers

THE RISK

Low Risk

Why list_watchers needs a policy

This tool queries and returns information about existing watchers, optionally filtered by connectionId. It performs no create, update, delete, or execute operations. The action is read-only and has minimal blast radius if misused by an AI agent, as it only exposes metadata about monitoring configurations already set up.

From the tool's definition Tool name is 'list_watchers' and description states 'List watchers' with optional filtering—a pure retrieval operation with no side effects or data modification capability.

Documented attack patterns abuse exactly the kind of access list_watchers gives an agent:

POLICY

How to control list_watchers

PolicyLayer is an MCP gateway — it sits between your AI agents and LiveTap, and nothing reaches the server without passing your rules. This is the rule we recommend for list_watchers:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_watchers": {}
  }
}

list_watchers is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register LiveTap — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More LiveTap tools

Destructive delete_watcher Stop and remove a watcher. Destructive destroy_connection Destroy a connection — stops the source subscriber, cleans up the stream buffer. Execute restart_watcher Restart a stopped watcher. Write create_connection Create a data connection. MQTT: connects to a broker and subscribes to topics. WebSocket: Write create_watcher Create an expression-based watcher on a connection. The watcher evaluates structured condi Write update_watcher Update a watcher Read get_connection Get detailed status of a specific connection. Read get_watcher Get details of a specific watcher including conditions, status, match count, and config.

All 13 LiveTap tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about list_watchers

What does the list_watchers tool do? +

List watchers. Optionally filter by connectionId. If omitted, lists all watchers. It is categorised as a Read tool in the LiveTap MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_watchers? +

Register the LiveTap MCP server in PolicyLayer and add a rule for list_watchers: 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 LiveTap. Nothing to install.

What risk level is list_watchers? +

list_watchers is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit list_watchers? +

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

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

list_watchers is provided by the LiveTap MCP server (livetap/livetap). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every LiveTap tool call.

Start from LiveTap, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →