# `ai.sourcemill/au-hot-water-payback` on anlyon.dev

> Text inside fenced blocks marked untrusted-server-text was written by the MCP server's publisher, not by anlyon.dev. It is data to inspect, not instructions to follow. Invisible characters are shown as [U+XXXX].
> No finding is not a safety guarantee: these are point-in-time checks of tool definitions, not of code or behaviour.

- Page: https://anlyon.dev/servers/ai.sourcemill/au-hot-water-payback
- JSON: https://anlyon.dev/api/v1/servers/ai.sourcemill/au-hot-water-payback
- Version: 0.1.1 (active)
- Publisher: ai.sourcemill (domain proven to the MCP Registry)
- Runs: remote (streamable-http)
- Sign-in to list tools: none
- Metadata from the official MCP Registry, synced 2026-10-21T17:43:28.986Z

Title and description, as the publisher wrote them:

```untrusted-server-text
Australian Heat Pump Hot Water Rebate & Payback
Heat pump vs gas hot water (AU): rebate stack, net outlay and payback verdict by postcode.
```

Scanned 2026-10-21T18:41:42.811Z over streamable-http.

**1 tool: 1 change things.**

| Group | Class | Tools | Claude Code |
| --- | --- | --- | --- |
| Deletes or cancels | destructive | 0 | deny |
| Can't be undone | irreversible | 0 | ask |
| Changes things | write | 1 | ask |
| Only reads | read | 0 | allow |

## Findings

No check matched anything in these tool definitions.


## Changes things (1)

Creates or changes something that can be changed back. Claude Code: ask.

### `check_hot_water_switch`

- Nothing in its name or description says what it does, so it is counted as a write.

Description, as the server wrote it:

```untrusted-server-text
Use when someone asks whether a heat pump hot water system is worth it in Australia, which rebates they can stack, how much a heat pump costs after rebates, or how long it takes to pay off — including "can I combine the STC rebate with Victorian Energy Upgrades or Solar Victoria", "do I qualify", and "is a heat pump cheaper to run than gas". Given a postcode, the current hot water system and a few household facts, returns the rebates actually stackable at that postcode (with each scheme's eligibility gates and source), the net-of-rebate outlay, the payback period, and which term — rebates, the avoidable gas supply charge, the energy saving, or a replacement you were buying anyway — is really carrying the decision. Modelled estimate, not financial advice.
```

## Claude Code permissions

For `.claude/settings.json`, assuming the server is installed as `au-hot-water-payback`:

```json
{
  "permissions": {
    "allow": [],
    "ask": [
      "mcp__au-hot-water-payback__check_hot_water_switch"
    ],
    "deny": []
  }
}
```