We have added buttons on Issue form view.
In form view we have added timer also to show total time spent from work started till now. Users can manually edit timesheet entry description or we have added special field on Issue for that where users can enter details of their work and that will be added as timesheet description.
There will be default description of Issue. We Capture start and stop time also on timesheet for more clear picture of work.
Project Issue Timesheet with Start Stop improvements to Simplify project Issue Usability