# run-build-job-scaler

`station__microgram__run-build-job-scaler` · external (needs EXECUTION_BACKEND_URL configured) · domain `microgram` · pv-relevance `pv-core`

Adaptive build parallelism scaler. Reads available_mb and cpu_cores, outputs optimal CARGO_BUILD_JOBS. Scales down under memory pressure, scales up when headroom exists. Closed-loop with build-memory-gate: gate decides GO/WARN/BLOCK, scaler decides HOW FAST.

> **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

- `crate_tier` *string* (required) — Input parameter: crate_tier
- `cpu_cores` *integer* (required) — Input parameter: cpu_cores
- `available_mb` *integer* (required) — Input parameter: available_mb

## Example call

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

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "station__microgram__run-build-job-scaler",
    "arguments": {
      "crate_tier": "",
      "cpu_cores": 0,
      "available_mb": 0
    }
  }
}
```

## Related

- [/tools](/tools) — all 3062 tools
- [/tools/microgram__run-build-job-scaler](/tools/microgram__run-build-job-scaler) — HTML page
- [/tools/microgram__run-build-job-scaler/json](/tools/microgram__run-build-job-scaler/json) — JSON form (agent-friendly)
- [/api/mcp](/api/mcp) — endpoint
- [/AGENTS.md](/AGENTS.md) — agent guide