On Web UI API Browser some commands have no translated description or have no description at all.
To get list of such:

1) by curl receive JSON reply to json_metadata request with 'Accept-Language:ru'
2) jq '.result.commands | keys[] as $k | "($k), (.[$k] | .doc)"' json-reply | grep -P '(, null|^[^а-яА-Я]*$)'

Result:

batch
command_defaults
cosentry_add
cosentry_del
cosentry_find
cosentry_mod
cosentry_show
dnsrecord_split_parts
hbacrule_add_sourcehost
hbacrule_remove_sourcehost
i18n_messages
kra_is_enabled
schema
vault_add_internal
vault_archive_internal
vault_mod_internal
vault_retrieve_internal
aci_add
aci_del
aci_find
aci_mod
aci_rename
aci_show
ca_is_enabled
dns_is_enabled
dnsrecord_delentry
idrange_add
idrange_mod
join
json_metadata
permission_add_member
permission_remove_member
privilege_remove_member
session_logout

Cause: the command description is taken from python docstring. Thus
commands should have them and should include the callings of gettext to be translated.

Fix is : https://github.com/freeipa/freeipa/pull/1996
As a countermeasure: https://github.com/freeipa/freeipa/pull/2046