<md-button class="md-raised md-primary" ng-click="$ctrl.requestAddCommentAction()">
    <md-tooltip>Add comment to list</md-tooltip>
    <i class="fa fa-fw fa-plus"></i>add comment
</md-button>

<md-button class="md-raised md-primary" ng-click="$ctrl.requestAddCommentAction()">
    <i class="fa fa-fw fa-plus"></i>add comment
</md-button>

Remove tooltip from Add Comment Button
Remove tooltip from Add Comment Button
