Good alerts are actionable and user-impact focused (symptom-based), with clear severity and a runbook link. Avoid alert fatigue by reducing noisy alerts, using proper thresholds, grouping, and paging only on real incidents (use error budgets).
Expanding on the short answer — what usually matters in practice:
A tiny example (an explanation template):
// Example: discuss trade-offs for "what-makes-a-good-alert-and-how-do-you-avoid-ale"
function explain() {
// Start from the core idea:
// Good alerts are actionable and user-impact focused (symptom-based), with clear severity an
}