While Tools can only be managed through the tool pipeline,  tool sessions can be managed on the backend in the /administrator interface.

User session limits (and tool preferences) can be found by following these steps:

1. Navigate to /administrator interface
2. Hover over Components and from the drop-down select Tools
3. Click on User Preferences
4. Number of sessions is dictated by the session class
   1. Default Class = 3
      1. Add another class by clicking "Custom" class, then enter the number for the user
5. If a user doesn't have an entry, you can create one for them