mark_device_known · Network Scanner MCP: Risk & Policy

WHAT IT DOES

What mark_device_known does on Network Scanner MCP

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

WHY IT NEEDS A POLICY

Why mark_device_known needs a policy

This tool creates or modifies metadata about devices (marking them as known/trusted, adding labels) rather than destructively deleting data. It is a reversible write operation that changes device classification state.

From the tool's definition Tool name 'mark_device_known' and description 'Mark a device as known/trusted with a label' indicate modification of device metadata/state by adding labels or trust status.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mark_device_known Rate-limited

mark_device_known 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": {
    "mark_device_known": {
      "limits": [
        {
          "counter": "mark_device_known_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 Network Scanner MCP, so you can run agents against it safely.

FAQ

Questions about mark_device_known

What does the mark_device_known tool do? +

Mark a device as known/trusted with a label. It is categorised as a Write tool in the Network Scanner MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on mark_device_known? +

Register the Network Scanner MCP server in PolicyLayer and add a rule for mark_device_known: 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 Network Scanner MCP. Nothing to install.

What risk level is mark_device_known? +

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

Can I rate-limit mark_device_known? +

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

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

mark_device_known is provided by the Network Scanner MCP server (marc-shade/network-scanner-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.