The atext file is the new accordance format for PCO compatible cross-platform files. (atext for texts, and atool for tools)
I don't know if you will have broken anything by doing what you've done, but the recommended thing to do is
Remove it from your library by right clicking and selecting 'remove item' from the drop down menu.
Then readd the tool by pressing the "+" button in the bottom left of the library pane and selecting "add new modules", then navigating to the atool and adding it back in.
I have found that sometimes this does not work, but if you delete the entry and you delete the file, then you can reinstall using easy install this has always worked when I have done it..
Edited by Ken Simpson, 25 May 2013 - 11:45 PM.