I see, very useful information.
I added in the addon in path: \design\themes\responsive\templates\addons\my_customaddon\blocks\product_tabs\mytemplate.tpl and I saw that tab was created automcatically in [Table: cscart_product_tabs_descriptions) but with empty name. eg tab_id 1, languge en and name empty.
Do you have any ideea where to mention the name of the tab to be save in database, in addon.xml, or i func.php or other place. Thank you!