Two shortcuts exist to reach this step:
The Parameter Details pane changes to reflect the type the parameter:
The new parameter appears in the parameter tree. It is highlighted as the currently selected entry, and its Help appears in the help pane.
If the parameter being added to the tree belongs to a section yet to be defined in the tree, both the section and parameter are added to the parameter tree when you click Add.
If the parameter being added to the parameter tree is an undocumented parameter, it appears in the parameter tree. However, if you hide undocumented parameters, you'll only be able to see parameters when you view undocumented parameters. See To show undocumented parameters:for details.