in fsi --- #help requires ;; to get help text.

fsi has a direct #help that displays the help text
````
F# Interactive directives:

#r "file.dll";; Reference (dynamically load) the given DLL
#I "path";; Add the given search path for referenced DLLs
#load "file.fs" ...;; Load the given file(s) as if compiled and referenced
#time ["on"|"off"];; Toggle timing on/off
#help;; Display help
#quit;; Exit

F# Interactive command line options:

See 'fsi --help' for options
````

However in order to get the text you have to actually type
#help ;;

Which if you need help is somewhat idiosyncratic ... or even unhelpful.