diag · Windows Operations MCP: Risk & Policy

WHAT IT DOES

What diag does on Windows Operations MCP

AI agents invoke diag to trigger actions in Windows Operations MCP. 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 diag needs a policy

Flushing the DNS cache is an active system operation that modifies the state of the Windows DNS resolver (irreversibly clears cached entries), and ipconfig execution triggers an external system command. While DNS cache flushing is not catastrophically destructive, it does cause side effects (network disruption, re-resolution latency) that go beyond a pure read.

From the tool's definition Flush DNS cache and return full ipconfig output

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

diag Rate-limited

diag 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": {
    "diag": {
      "limits": [
        {
          "counter": "diag_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 Windows Operations MCP, so you can run agents against it safely.

FAQ

Questions about diag

What does the diag tool do? +

Flush DNS cache and return full ipconfig output. It is categorised as a Execute tool in the Windows Operations MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on diag? +

Register the Windows Operations MCP server in PolicyLayer and add a rule for diag: 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 Windows Operations MCP. Nothing to install.

What risk level is diag? +

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

Can I rate-limit diag? +

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

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

diag is provided by the Windows Operations MCP server (sandraschi/windows-operations-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.