[guntars]

I wouldn't go as far to say that having undocumented magic comments doesn't add complexity. From a very surface level, sure, the parser is the same, but now every tool that works with the Go language needs to be aware of these. Linters, for example, need to not complain about the missing space in front of the comment, but only if the comment starts with "go:".

Ultimately anything that changes how the program is executed is going to add complexity, so they might as well "make it official" and add a keyword for it.