# chemistry-first-law-closed

`station__chemistry__chemistry-first-law-closed` · external (needs EXECUTION_BACKEND_URL configured) · domain `chemistry` · pv-relevance `pv-adjacent`

ΔU = Q - W (Conservation of Energy)

> **Note:** This tool routes through an external execution backend. If `EXECUTION_BACKEND_URL` is unset on the server, calls return JSON-RPC error `-32603 "Tool execution backend not configured"`. Tools with `backend: native` execute in-process and are always callable.

## Agent metadata

- `idempotent`: unknown
- `read_only`: unknown
- `expected_latency_ms`: unknown (not yet contract-tested)
- `cost_tokens_estimate`: unknown

## Input schema

- `heat_in` *number* (required) — Heat added to system (J)
- `u_initial` *number* (required) — Initial internal energy (J)
- `work_out` *number* (required) — Work done by system (J)

## Example call

```json
POST /api/mcp
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "station__chemistry__chemistry-first-law-closed",
    "arguments": {
      "heat_in": 0,
      "u_initial": 0,
      "work_out": 0
    }
  }
}
```

## Related

- [/tools](/tools) — all 3062 tools
- [/tools/chemistry__chemistry-first-law-closed](/tools/chemistry__chemistry-first-law-closed) — HTML page
- [/tools/chemistry__chemistry-first-law-closed/json](/tools/chemistry__chemistry-first-law-closed/json) — JSON form (agent-friendly)
- [/api/mcp](/api/mcp) — endpoint
- [/AGENTS.md](/AGENTS.md) — agent guide