TBH a lot of my commits which follow that "Working on [...]" log pattern are not modeling coherent units of change (why I often cannot come up with a message better than "Working on [...]") but just the result of me taking a breather, like making myself a cup of coffee. The "Completed [...]" message indicates the end of that unit of work, and there I often write a much more detailed message along with the first "Started working on [...]" type messages when I just start working on something. If you average commits like once every 15 mins, then those "Working on [...]" messages are more like in-betweeners for what someone might commit in one bulkier commit with a more detailed message.