update_property · REP Helper MCP: Risk & Policy

WHAT IT DOES

What update_property does on REP Helper

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

WHY IT NEEDS A POLICY

Why update_property needs a policy

This tool creates or modifies data in a reversible manner (Write category). The severity is medium because: (1) it modifies property records that are used for IRS tax documentation, so errors could affect tax compliance, (2) changes are reversible/updatable, and (3) the blast radius is limited to property metadata rather than financial transactions themselves.

From the tool's definition Tool name 'update_property' combined with description 'Update an existing property. Only include fields you want to change' indicates modification of existing data records.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_property Rate-limited

update_property 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_property": {
      "limits": [
        {
          "counter": "update_property_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 REP Helper, so you can run agents against it safely.

FAQ

Questions about update_property

What does the update_property tool do? +

Update an existing property. Only include fields you want to change. It is categorised as a Write tool in the REP Helper 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_property? +

Register the REP Helper MCP server in PolicyLayer and add a rule for update_property: 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 REP Helper. Nothing to install.

What risk level is update_property? +

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

Can I rate-limit update_property? +

Yes. Add a rate_limit block to the update_property 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_property completely? +

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

update_property is provided by the REP Helper MCP server (rephelper-ai/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.