Regarding ActionLayout annotation, the text specified with the 'describedAs' feature will sometimes not show up.
Reason: bootstrap (on the client-side) will modify the DOM such that HTML links will no longer work as intended. (ISIS Actions/Buttons are HTML links.)
1) Server sends ...
<li title="described as"><a ... /></li>
2) bootstrap makes changes (adds the 'title' attribute, where there was non provided by the server)
<li title="described as"><a title="" ... /></li>
3) now when we mouse-over the link, no tooltip is shown
For a possible solution see: