# mortgage_calculator

Calculate mortgage details.

Agent View of the PolicyLayer registry record for `mortgage_calculator`. HTML page: https://policylayer.com/tools/io-tinyfn-tinyfn/mortgage-calculator

## Facts

- Tool: `mortgage_calculator`
- Server: TinyFn (`https://api.tinyfn.io/mcp/all/`) — https://policylayer.com/tools/io-tinyfn-tinyfn.md
- Homepage: https://github.com/tinyfn-io/tinyfn-mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 4 (2 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `rate` | number | yes | Annual interest rate (percentage) |
| `years` | integer | no | Loan term in years |
| `home_price` | number | yes | Home price |
| `down_payment` | number | no | Down payment |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "mortgage_calculator",
    "arguments": {
      "rate": 0,
      "home_price": 0
    }
  }
}
```

## Why mortgage_calculator is rated Low

This tool performs mathematical calculations on mortgage parameters (principal, interest rate, term, etc.) to return computed values like payment amounts or amortization schedules. It is deterministic computation with no side effects—no data is created, modified, deleted, or financial transactions initiated. The operation is read-like: it takes inputs and returns calculated results.

From the tool's own definition: "Tool name 'mortgage_calculator' and description 'Calculate mortgage details' indicate a calculation/query operation that retrieves or computes mortgage information based on input parameters without modifying any data or triggering financial transactions."

## Use case

AI agents call mortgage_calculator to retrieve information from TinyFn without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches TinyFn:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "mortgage_calculator": {}
  }
}
```

## Other tools on TinyFn (571)

- `array_compact` — Destructive — https://policylayer.com/tools/io-tinyfn-tinyfn/array-compact.md
- `array_dedupe` — Destructive — https://policylayer.com/tools/io-tinyfn-tinyfn/array-dedupe.md
- `truncate_2` — Destructive — https://policylayer.com/tools/io-tinyfn-tinyfn/truncate-2.md
- `generate_hmac` — Execute — https://policylayer.com/tools/io-tinyfn-tinyfn/generate-hmac.md
- `random_float_2` — Execute — https://policylayer.com/tools/io-tinyfn-tinyfn/random-float-2.md
- `random_string_2` — Execute — https://policylayer.com/tools/io-tinyfn-tinyfn/random-string-2.md
- `random_weighted_choice` — Execute — https://policylayer.com/tools/io-tinyfn-tinyfn/random-weighted-choice.md
- `roll_dice` — Execute — https://policylayer.com/tools/io-tinyfn-tinyfn/roll-dice.md
- `null` — Other — https://policylayer.com/tools/io-tinyfn-tinyfn/null.md
- `absolute_value` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/absolute-value.md
- `acres_to_hectares` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/acres-to-hectares.md
- `add` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/add.md
- `adler32_checksum` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/adler32-checksum.md
- `analogous_colors` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/analogous-colors.md
- `analyze_password` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/analyze-password.md
- `array_difference` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-difference.md
- `array_first` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-first.md
- `array_frequency` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-frequency.md
- `array_interleave` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-interleave.md
- `array_intersection` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-intersection.md
- `array_last` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-last.md
- `array_nth` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-nth.md
- `array_partition` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-partition.md
- `array_repeat` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-repeat.md
- `array_reverse` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-reverse.md
- `array_rotate` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-rotate.md
- `array_slice` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-slice.md
- `array_symmetric_difference` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-symmetric-difference.md
- `array_union` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-union.md
- `array_unzip` — Read — https://policylayer.com/tools/io-tinyfn-tinyfn/array-unzip.md
- …and 541 more: https://policylayer.com/tools/io-tinyfn-tinyfn.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-tinyfn-tinyfn · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-tinyfn-tinyfn