Here is how add tooltip help to list entries.
You need modify or create new list template and add title attribute.
In this example I modify APEX build in theme 1 Horizontal Images with Label List template.
Add to first div in List Template Current and List Template Noncurrent title attribute like in below picture.
Edit your list and change it to use new template.
Edit your list entries and fill to first User Defined Attributes help text you like have for list entry.
Now when you run page and hower mouse over list entry, you can see tooltip help.