file_id	IN:	File identifier returned by Hopen
	description	IN:	Sequence of ASCII characters (may include NULL or '\0')
	desc_len	IN:	Length of the description

	Purpose	Adds a file description to a file.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	These annotations are associated with the file, not with any particular object within the file. The parameter description can contain any sequence of ASCII characters. It does not have to be a string. Use the general purpose routines Hopen and Hclose to manage file access as the file annotation routines will not open and close HDF files.

	FORTRAN	integer function daafds(file_id, description, desc_len)
		integer file_id, desc_len
		character*(*) description