I always liked the notions of coupling and cohesion because they are simple to understand and you can see at the glance of an eye if a particular bit of code wo

I always liked the notions of coupling and cohesion because they are simple to understand and you can see at the glance of an eye if a particular bit of code would have good metrics for those, without actually bothering with the metrics. E.g. long list of parameters or imports == high coupling, large number of fuctions in a module == low cohesion. Specifying exactly how much isn't that useful. It's easier to think in terms of "relative to the rest of the code". Debating what is too high or too low even less so. But if you are struggling with working with a particular bit of code, being able to identify why it is hard to deal with is useful; especially if you know how to fix it. But mostly metrics should not be telling you things you can't already know just looking at the code; if it looks complicated, it probably is. Metrics only become useful when you need to tell without looking. Sometimes that's useful.