1- Go to Personal zone > Own contents > Tools administration. On the screen you will see a list of the tools assigned to you. From this page you can edit features of your own tools, such as who can have access to each of them or the specific parameters for each type of tool.

2- Click on Edit.

3- You will see a screen where you can set the properties of each type of tool.

Visibility determines which type of user can see each of the tools. To set Visibility, select Private or All users from the pull-down menu, according to whether you want your tool (Blog, Wiki, etc.) to be private or public.

You can also enable or disable comments.