# annuity

Annuity Present / Future Value — Compute the present or future value of an ordinary annuity or annuity-due.

Agent View of the PolicyLayer registry record for `annuity`. HTML page: https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/annuity

## Facts

- Tool: `annuity`
- Server: Gateway (`https://wingmanprotocol.com/mcp`) — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway.md
- Homepage: https://github.com/WingmanProtocol-Agent-Gateway/wingman-agent-gateway
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 5 (3 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `due` | boolean | no | True for annuity-due (default ordinary) |
| `mode` | string | no | pv or fv |
| `rate` | number | yes | Rate per period as a decimal |
| `payment` | number | yes | Payment per period |
| `periods` | integer | yes | Number of periods |

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": "annuity",
    "arguments": {
      "rate": 0,
      "payment": 0,
      "periods": 0
    }
  }
}
```

## Why annuity is rated Low

This is a financial calculator that performs mathematical computations on annuity parameters and returns results. It does not move money, execute trades, create financial obligations, or modify persistent state. The tool is analogous to other calculators in the sibling tool set (base_convert, bayes, amortization_schedule), which are Read-category utilities.

From the tool's own definition: "Tool computes and returns present or future value calculations for annuity financial instruments. Description uses passive voice ('Compute the present or future value') indicating data retrieval/calculation without state modification or money movement."

## Use case

AI agents call annuity to retrieve information from Gateway 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 Gateway:

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

## Other tools on Gateway (270)

- `cancel_watch` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/cancel-watch.md
- `forget_memories` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/forget-memories.md
- `text_truncate_ellipsis` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/text-truncate-ellipsis.md
- `vault_delete` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/vault-delete.md
- `arena_call` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/arena-call.md
- `bitwise` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/bitwise.md
- `browse` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse.md
- `browse_back` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-back.md
- `browse_click` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-click.md
- `browse_close` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-close.md
- `browse_evaluate` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-evaluate.md
- `browse_fill` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-fill.md
- `browse_navigate` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-navigate.md
- `browse_open` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-open.md
- `browse_select` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-select.md
- `browse_solve_challenge` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-solve-challenge.md
- `browse_type` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-type.md
- `browse_wait_for` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-wait-for.md
- `coach_mission` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/coach-mission.md
- `dice_notation_roll` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/dice-notation-roll.md
- `gen_avatar_video` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-avatar-video.md
- `gen_id_portrait` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-id-portrait.md
- `gen_image` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-image.md
- `gen_video` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-video.md
- `hmac` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/hmac.md
- `markdown_to_html` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/markdown-to-html.md
- `matrix` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/matrix.md
- `regex_tester` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/regex-tester.md
- `request_handoff` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/request-handoff.md
- `retry_backoff` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/retry-backoff.md
- …and 240 more: https://policylayer.com/tools/com-wingmanprotocol-agent-gateway.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=com-wingmanprotocol-agent-gateway · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-wingmanprotocol-agent-gateway