# `uk.co.reliness/finance-formulas` 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/uk.co.reliness/finance-formulas
- JSON: https://anlyon.dev/api/v1/servers/uk.co.reliness/finance-formulas
- Version: 1.5.0 (active)
- Publisher: uk.co.reliness (domain proven to the MCP Registry)
- Runs: remote (streamable-http)
- Sign-in to list tools: none
- Metadata from the official MCP Registry, synced 2026-11-07T12:18:07.766Z

Title and description, as the publisher wrote them:

```untrusted-server-text
UK Data: Finance formulas
Compound and simple interest, investment growth, future value, CAGR, dividends and tax at a rate
```

Scanned 2026-11-07T12:18:12.088Z over streamable-http.

**10 tools: 10 change things.**

| Group | Class | Tools | Claude Code |
| --- | --- | --- | --- |
| Deletes or cancels | destructive | 0 | deny |
| Can't be undone | irreversible | 0 | ask |
| Changes things | write | 10 | ask |
| Only reads | read | 0 | allow |

## Exfil surface

No private-data -> untrusted-input -> outbound path in this server alone: no tool is tagged private-data or outbound.

| Tag | Meaning | Tools |
| --- | --- | --- |
| private-data | Reads files, mail, messages, databases, secrets, calendars or repositories. | none |
| untrusted-input | Brings in text someone else can write: web pages, inbound email, messages, issues and comments. | `mcp__finance-formulas__cagr` `mcp__finance-formulas__calculate_discount` `mcp__finance-formulas__calculate_discounted_price` `mcp__finance-formulas__calculate_dividend_per_share` `mcp__finance-formulas__calculate_interest` `mcp__finance-formulas__calculate_investment_return` `mcp__finance-formulas__calculate_tax` `mcp__finance-formulas__compound_interest` `mcp__finance-formulas__future_investment_value` `mcp__finance-formulas__project_investment_growth` |
| outbound | Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL. | none |

## Findings

No check matched anything in these tool definitions.


## Changes things (10)

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

### `cagr`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates the Compound Annual Growth Rate (CAGR) using the formula CAGR = (end_value/start_value)^(1/years) - 1. Returns the annualized rate of return as a percentage. (cost: 1 credit)
```

### `calculate_discount`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates the discounted price after applying a percentage discount to the original price. Returns both discount amount and final price. (cost: 1 credit)
```

### `calculate_discounted_price`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates the final price after applying a discount percentage to the original price, rounded to 2 decimal places. (cost: 1 credit)
```

### `calculate_dividend_per_share`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates the dividend per share by dividing total dividend payout by number of outstanding shares. Returns the quarterly dividend amount per share rounded to 2 decimal places. (cost: 1 credit)
```

### `calculate_interest`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates simple interest using the formula: Interest = Principal × Rate × Time. Rate should be provided as a percentage and time in years. (cost: 1 credit)
```

### `calculate_investment_return`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates the return on investment using compound interest formula. Returns the final amount and total return given an initial deposit, annual interest rate (as a percentage), and investment period in years. (cost: 1 credit)
```

### `calculate_tax`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates the tax amount by applying a tax rate percentage to an income or price amount. Formula: amount × (rate / 100). (cost: 1 credit)
```

### `compound_interest`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates compound interest using the formula A = P(1 + r/n)^(nt), where A is final amount, P is principal, r is annual rate, n is compounding frequency per year, and t is time in years. (cost: 1 credit)
```

### `future_investment_value`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Calculates the future value of an investment using compound interest formula: FV = PV × (1 + r)^n, where r is annual interest rate and n is years. (cost: 1 credit)
```

### `project_investment_growth`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Projects investment growth over years using compound interest with optional annual additions and inflation adjustment. Formula: FV = PV(1+r)^n + PMT×[((1+r)^n - 1)/r], with each annual addition made at the end of the year. (cost: 1 credit)
```

## Claude Code permissions

For `.claude/settings.json`, assuming the server is installed as `finance-formulas`:

```json
{
  "permissions": {
    "allow": [],
    "ask": [
      "mcp__finance-formulas__calculate_discounted_price",
      "mcp__finance-formulas__calculate_investment_return",
      "mcp__finance-formulas__future_investment_value",
      "mcp__finance-formulas__calculate_interest",
      "mcp__finance-formulas__calculate_discount",
      "mcp__finance-formulas__calculate_tax",
      "mcp__finance-formulas__project_investment_growth",
      "mcp__finance-formulas__compound_interest",
      "mcp__finance-formulas__cagr",
      "mcp__finance-formulas__calculate_dividend_per_share"
    ],
    "deny": []
  }
}
```

Capability tags behind the rules (a read tagged outbound is asked about):

- `mcp__finance-formulas__calculate_discounted_price`: untrusted-input
- `mcp__finance-formulas__calculate_investment_return`: untrusted-input
- `mcp__finance-formulas__future_investment_value`: untrusted-input
- `mcp__finance-formulas__calculate_interest`: untrusted-input
- `mcp__finance-formulas__calculate_discount`: untrusted-input
- `mcp__finance-formulas__calculate_tax`: untrusted-input
- `mcp__finance-formulas__project_investment_growth`: untrusted-input
- `mcp__finance-formulas__compound_interest`: untrusted-input
- `mcp__finance-formulas__cagr`: untrusted-input
- `mcp__finance-formulas__calculate_dividend_per_share`: untrusted-input

## Remote posture

What an anonymous client saw at the remote endpoint, last 2026-11-08T06:21:54.855Z, unchanged since 2026-11-08T06:21:54.855Z. No credentials were sent and no tool was called. Values are shown as the endpoint returned them. Method: https://anlyon.dev/methodology#remote-posture

| Fact | Observed |
| --- | --- |
| Reachable | `yes` |
| HTTP status of an anonymous initialize | `200` |
| tools/list served without credentials | `yes` |
| Tools that change things, listed without credentials | `10` |
| Protocol version | `2025-06-18` |
| WWW-Authenticate on 401 | `not observed` |
| resource_metadata in WWW-Authenticate | `none` |
| RFC 9728 protected resource metadata | `none` |
| Authorization servers | `none` |
| Legacy HTTP+SSE transport | `no` |
| Dynamic client registration | `not observed` |
| Client ID metadata documents | `not observed` |

- **warn** Tools that change things, listed to anyone ([unauth-remote-writes](https://anlyon.dev/methodology#unauth-remote-writes))

```untrusted-server-text
The endpoint served tools/list without credentials, and the list has 10 tools that change things (10 write). Whether a call also works without credentials was not tested: tools are never called.

https://ukdata.reliness.co.uk/mcp/finance-formulas: tools/list returned 10 tools to an anonymous client, including calculate_discounted_price (write), calculate_investment_return (write), future_investment_value (write), calculate_interest (write), calculate_discount (write) and 5 more
```