update_context_file · Network Device Assistant MCP

WHAT IT DOES

What update_context_file does on Network Device Assistant

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

WHY IT NEEDS A POLICY

Why update_context_file needs a policy

The tool creates or modifies data reversibly by appending to a file, which is characteristic of Write category. It does not delete data (not Destructive), execute commands (not Execute), move money (not Financial), or merely retrieve data (not Read).

From the tool's definition Tool description states 'Append new information to a context/memory file' — this is a write operation that modifies data (the context file) in a reversible manner (appending can be undone by removing the appended lines).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_context_file Rate-limited

update_context_file 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": {
    "update_context_file": {
      "limits": [
        {
          "counter": "update_context_file_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 Device Assistant, so you can run agents against it safely.

FAQ

Questions about update_context_file

What does the update_context_file tool do? +

Append new information to a context/memory file. It is categorised as a Write tool in the Network Device Assistant MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_context_file? +

Register the Network Device Assistant MCP server in PolicyLayer and add a rule for update_context_file: 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 Device Assistant. Nothing to install.

What risk level is update_context_file? +

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

Can I rate-limit update_context_file? +

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

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

update_context_file is provided by the Network Device Assistant MCP server (mgarabito/network-device-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.