update_device

Update a device registry entry.

SERVERHa Nexus Agent SOURCEfistacho/ha-nexus-agent

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/fistacho-ha-nexus-agent/update-device.md

WHAT IT DOES

What update_device does on Ha Nexus Agent

AI agents use update_device to create or update resources in Ha Nexus Agent, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Ha Nexus Agent environment.

RISK

Why update_device is rated Medium

The tool updates device registry metadata, which is a Write operation (creates or modifies data reversibly). While it affects smart home configuration, the change is not destructive and can be reverted. Severity is medium because misconfiguration of device entries could disrupt home automation logic, but it does not irreversibly delete data, move money, or execute arbitrary commands.

From the tool's definition Tool name is 'update_device' and description states 'Update a device registry entry' — this modifies existing data in a reversible manner without deletion or financial impact.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs update_device safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Ha Nexus Agent, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For update_device, this is the rule to start with:

update_device Rate-limited

update_device 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_device": {
      "limits": [
        {
          "counter": "update_device_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Ha Nexus Agent, apply this rule, and every update_device call is checked against it from then on.

FAQ

Questions about update_device

What does the update_device tool do? +

Update a device registry entry. It is categorised as a Write tool in the Ha Nexus Agent 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_device? +

Register the Ha Nexus Agent MCP server in PolicyLayer and add a rule for update_device: 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 Ha Nexus Agent. Nothing to install.

What risk level is update_device? +

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

Can I rate-limit update_device? +

Yes. Add a rate_limit block to the update_device 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_device completely? +

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

update_device is provided by the Ha Nexus Agent MCP server (fistacho/ha-nexus-agent). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Ha Nexus Agent, and thousands of servers like it.

This server

All 276 Ha Nexus Agent tools →

Across the catalogue

aroflo_create_or_update_record on AroFlo MCP →team_manager_update_budget on Team Manager MCP → The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →