When adding periods within a list of completions Sublime Text blocks other/default completions from showing.
Ex:
prevents other completions from showing
"angular.copy\tAngularJS", "angular.copy(${1:source}${2:, ${3:destination}})"]
allows other completions to show
"angularcopy\tAngularJS", "angular.copy(${1:source}${2:, ${3:destination}})"]