do_update · Nexus Memory MCP: Risk & Policy

WHAT IT DOES

What do_update does on Nexus Memory

AI agents invoke do_update to trigger actions in Nexus Memory. 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 do_update needs a policy

This tool performs a remote code fetch from GitHub and reinstalls software on the host, which constitutes executing external operations with significant blast radius. A misuse could install malicious code, break the running service, or introduce supply-chain compromises.

From the tool's definition 'Pulls from GitHub and reinstalls' — this triggers an external network operation and re-executes an installation process on the host system

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

do_update Rate-limited

do_update 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": {
    "do_update": {
      "limits": [
        {
          "counter": "do_update_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 Nexus Memory, so you can run agents against it safely.

FAQ

Questions about do_update

What does the do_update tool do? +

Update Nexus Memory to the latest version. Pulls from GitHub and reinstalls. It is categorised as a Execute tool in the Nexus Memory MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on do_update? +

Register the Nexus Memory MCP server in PolicyLayer and add a rule for do_update: 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 Nexus Memory. Nothing to install.

What risk level is do_update? +

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

Can I rate-limit do_update? +

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

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

do_update is provided by the Nexus Memory MCP server (neboy72/nexus-memory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.