When you leave a comment on a task, the task creator will get a notification.

If you were assigned an individually assigned task ( you can learn more about individually assigned and group tasks here), the comments that you leave will only notify the creator of the task. The other task assignees will not see your comments.

However, if you were assigned a group task, all the members of the group task will get notified whenever you leave a comment as it is a task that you are supposed to complete together.

In a group task scenario, all the comments will be visible to all the task assignees.