# calculate_bearing

Calculate bearing (direction) between two coordinates.

Agent View of the PolicyLayer registry record for `calculate_bearing`. HTML page: https://policylayer.com/tools/io-tinyfn-tinyfn/calculate-bearing

## Facts

- Tool: `calculate_bearing`
- 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 (4 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `lat1` | number | yes | Latitude of start point |
| `lat2` | number | yes | Latitude of end point |
| `lon1` | number | yes | Longitude of start point |
| `lon2` | number | yes | Longitude of end point |

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": "calculate_bearing",
    "arguments": {
      "lat1": 0,
      "lat2": 0,
      "lon1": 0,
      "lon2": 0
    }
  }
}
```

## Why calculate_bearing is rated Low

This is a pure computational/query operation that takes geographic coordinates as input and returns a calculated bearing value. It has no side effects, does not modify any data, does not execute external commands, and does not move money. It falls squarely into the Read category as a mathematical/analytical function.

From the tool's own definition: "Tool 'calculate_bearing' performs a calculation of directional bearing between two geographic coordinates. It retrieves/computes output based on input parameters with no data modification, deletion, or external operation execution."

## Use case

AI agents call calculate_bearing 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": {
    "calculate_bearing": {}
  }
}
```

## 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`

---

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