get_help_text() function problem

If I create MyClass.m with the following content:

##
## myclass:  do something
##

classdef MyClass
## methods
end

and then run

[t,f]=get_help_text('MyClass')

I get the results

t =
f = Not documented

I've tried to look at other classdef examples from Octave but don't see how
to fix this.
Can someone help me?