I would like to be able to specify output format by myself with comman line switches. Consider adding --format switch with some substitute variables like this:
%a - application name
%t - message title
%b - message body
%c - count
%i - id
%ps - preview summary
%pb - preview body
<here should be a few more>

As default format I propose following string
"%a - %c %t\n%b\n\n"

It should be handy to add a couple shorthand switches for common variants of requests. Like --oneline for
--format "%a - %c %t\n"
and --raw for complete listing of all parameters of notification.