You don’t need to do this. All your documents already have an item link as soon as they enter DT (you know that because you just copied it!). You gain nothing by putting the item link in the URL field, and I actually wonder if you’re causing your future self a problem because it’s an unexpected behaviour (e.g. how can DT open a URL that points to the file you’re already in?).
For your job summary file, you just need to copy and paste the item link into your note, there are no additional steps needed.