# compute_ev

Compute EU261 expected value for a trip: net cost after compensation probability

Agent View of the PolicyLayer registry record for `compute_ev`. HTML page: https://policylayer.com/tools/dev-danielsuchan-eu261/compute-ev

## Facts

- Tool: `compute_ev`
- Server: EU261 Flight Compensation (`https://eu261.danielsuchan.dev/mcp`) — https://policylayer.com/tools/dev-danielsuchan-eu261.md
- Homepage: https://github.com/MrSucik/eu261-mcp
- Risk category: Read (Low risk)
- Registry record: grade C, identity unverified
- Server auth posture: open
- Server CORS policy: *
- Server rate-limited: no
- Parameters: 4 (4 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `origin` | string | yes | Origin IATA code |
| `fare_eur` | number | yes | Round-trip fare in EUR |
| `destination` | string | yes | Destination IATA code |
| `routing_type` | string | yes | Routing type — determines payable-delay probability |

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": "compute_ev",
    "arguments": {
      "origin": "<origin>",
      "fare_eur": 0,
      "destination": "<destination>",
      "routing_type": "<routing_type>"
    }
  }
}
```

## Why compute_ev is rated Low

This tool performs a calculation/computation based on input data to derive an expected value. It retrieves no external state and modifies nothing — it is purely a mathematical/analytical function. No side effects, no data written, no commands executed.

From the tool's own definition: "Compute EU261 expected value for a trip: net cost after compensation probability"

Risk signals: Accepts file system path (destination)

## Use case

AI agents call compute_ev to retrieve information from EU261 Flight Compensation 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 EU261 Flight Compensation:

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

## Other tools on EU261 Flight Compensation (5)

- `check_eligibility` — Read — https://policylayer.com/tools/dev-danielsuchan-eu261/check-eligibility.md
- `distance` — Read — https://policylayer.com/tools/dev-danielsuchan-eu261/distance.md
- `get_price_history` — Read — https://policylayer.com/tools/dev-danielsuchan-eu261/get-price-history.md
- `list_airports` — Read — https://policylayer.com/tools/dev-danielsuchan-eu261/list-airports.md
- `record_price` — Write — https://policylayer.com/tools/dev-danielsuchan-eu261/record-price.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=dev-danielsuchan-eu261 · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dev-danielsuchan-eu261