While it is easy to enable a certificate again after one disabled it by mistake if one does know the feature, this is practically impossible for people who don't.

Please

• rename the action to "Disable and Hide Certificate" resp. "Enable and Show Certificate"
• add a confirmation dialog after choosing the action (only for the "Disable" one) with the option to not show the dialog again

Text proposal:

Do you really want to disable and hide the certificate ABC? 
Disabled certificates are not offered when selecting a certificate to sign with or to encrypt for and are only shown with the "Disabled" filter.
You can undo this action by going to the "Disabled" filter to view and enable the certificate again.