Most (if not all) of the feature clauses does not have any comment
usually we use

feature -- Access
   --mainly for attributes, functions
feature -- Change
  -- mainly for procedure that change Current ... such as set_foo , add_element, wipe_out, and so on
feature -- Operation
  -- could be for specific operation such as "process" ...
feature -- Conversion
  -- usually conversion to string ... text_representation, out, to_string, to_array, to_json, ...
feature {NONE} -- Implementation
  -- for implementation routines, ...
And of course you can use your own comment for feature clause