The current documentation on reverse reads:
This setting is ignored if use_age is True.
This does not reflect reality. The two following invocations with different values for reverse differ in output
--request_timeout 600 show-indices --filter_list '[{"filtertype":"pattern","kind":"prefix","value":"envoy"},{"filtertype":"count","count":'5',"reverse":"True","use_age":"True","source":"creation_date"}]'
--request_timeout 600 show-indices --filter_list '[{"filtertype":"pattern","kind":"prefix","value":"envoy"},{"filtertype":"count","count":'5',"reverse":"False","use_age":"True","source":"creation_date"}]'