Adding text to PDF using Adobe Reader in OS X As can be seen from the screenshot, I have selected "Add text at cursor" and entered the desired text.

But as can also be seen - there is only a tiny very narrow entry there - I can not even discern if any text were actually being displayed.

Adding text should be a simple procedure. What am I missing here?
I guess we can assume that the document does not fillable fields (because if it had, the question would not have come up).

The "Add text at cursor" tool is a markup tool, used for correction text. It sets a marker in the text, and the text to add is contained in the popup.

The suitable Comment tool for this purpose ("filling" out a form) would be the Add Text Comment tool.