An application's metrics names and types make up an implicit contract which consequences of ignoring can be serious.
Metric are used by systems admins to configure monitoring systems. Good metric names accurately and consistently convey meaning of the associated metric data. Admins should not have to look at the application code to understand what each metric represents. The name of a metric is often the only documentation available. Critical human decisions may have to be quickly made based on metrics, in these situations, their names should be as helpful and trustable as possible.
Dashboards and alerting systems entirely depend on the metrics applications provides them. Changing the identifiers or meaning of the metrics will break these downstream applications, negating the very reason to emit metrics in the first place :
- Alarms that shouldn't have gone off will go off