This is missing the service ordering instructions which are already documented for The snap format .
before
Type: Array of string
List of applications that are ordered to be started before <app-name>. Applications must be part of the same snap. Requires daemon to be set as the snap type. (snapd 2.31+)
after
Type: Array of string
List of applications that are ordered to be started after <app-name>. Applications must be part of the same snap. Requires daemon to be set as the snap type. (snapd 2.31+)