Improve phrasing.

Thanks to u for the feedback!

wiki/src/contribute/working_together/roles/foundations_team.mdwn

@@ -171,11 +171,12 @@ Cookie](https://www.benday.com/2016/10/21/scrum-dont-lick-the-cookie/).
 
 A ticket [owned by the Foundations
 Team](https://redmine.tails.boum.org/code/projects/tails/issues?query_id=307)
-should have the _Assignee_ field set if, and only if, at least one of
-these conditions is met:
+should not be assigned to anyone in general. But we do assign a ticket
+if at least one of these conditions is met:
 
- - It is the parent ticket for a large project that need someone to
-   coordinate our efforts.
+ - It is about the parent ticket for a large project with several
+   subtasks that will be tackled by different people, and we need
+   someone to coordinate the project.
 
  - The task is both important and urgent.