High CPU usage alert rule for Prometheus

alert.rules.yml

groups:
- name: example
  rules:
  # Alert for any cluster that has average CPU idle < 50%
  - alert: HighUsage
    expr: avg(irate(node_cpu_seconds_total{mode="idle"}[1m]) * 100) < 50
    for: 1m
    annotations:
      summary: "High usage on {{ $labels.instance }}"
      description: "{{ $labels.instance }} has a average CPU idle (current value: {{ $value }}s)"

Thank you :)