block_client · UniFi MCP Server MCP: Risk & Policy

WHAT IT DOES

What block_client does on UniFi MCP Server

AI agents invoke block_client to trigger actions in UniFi MCP Server. 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 block_client needs a policy

Blocking a client is an access-control enforcement action that actively prevents a device from using the network. It triggers an external operation on the UniFi infrastructure with immediate effect. While potentially reversible (there is a sibling 'unblock_client' tool), the act itself is an execution of a network policy change rather than a simple data write.

From the tool's definition Block a client from accessing the network

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

block_client Rate-limited

block_client 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": {
    "block_client": {
      "limits": [
        {
          "counter": "block_client_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 UniFi MCP Server, so you can run agents against it safely.

FAQ

Questions about block_client

What does the block_client tool do? +

Block a client from accessing the network. It is categorised as a Execute tool in the UniFi MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on block_client? +

Register the UniFi MCP Server MCP server in PolicyLayer and add a rule for block_client: 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 UniFi MCP Server. Nothing to install.

What risk level is block_client? +

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

Can I rate-limit block_client? +

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

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

block_client is provided by the UniFi MCP Server MCP server (nntkio/unifimcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.