It is not clear (to me) what you are trying to achieve with the "description" key.

Perhaps you are trying to store additional (hidden) information in the form, that you can re-use when you receive user response. If this is your objective, you can use several "hidden" fields, with values. These can be retrieved via the usual $cgi->param syntax.

If the "description" is for the benefit of the form user, perhaps you are looking for the "labels" key.

From the CGI docs:

The optional fifth argument is a pointer to an associative array relating the checkbox values to the user-visible labels that will be printed next to them (-labels). If not provided, the values will be used as the default.

It is not clear from the docs whether or not this is applicable to the "append" method. "label" is a valid key when creating the checkbox.