Yes, and so is declaring what exceptions a function can throw (checked exceptions in Java).
> Why is it bad to have functions annotated with this meta data? The functions behave in a fundamentally different way whether you give them special annotations/syntax or not. Shouldn't different things look different?
It really isn't a problem. The article makes people think they've discovered some clever gotcha when they first read it, but IMHO people who sit down for a bit and think through the issue come to the same conclusion you have - Function coloring isn't a problem in practice.