How to read tikz/pgf and tcolorbox manuals

You may think of /tikz, /pgf and /tcb as directories, and /tikz/cs and /pgf/number format as a subdirectories. You could, for instance, say

\pgfkeys{/pgf/number format/.cd,fixed,fixed zerofill,precision=2} 

to switch to /pgf/number format directory, and then set the fixed, fixed zerofill and precision=2 keys (this example is from p. 1049 of pgf manual v3.1.5). Among other things, these directories allow us to avoid running out of name space.

So from

/tikz/current point is local=⟨boolean⟩

you learn that

1. current point is local is in the /tikz directory (and not in /pgf, say), and
2. it is a boolean, meaning you should feed it with true or false (but not dimensions, say).