Is the use of the present perfect necessary in this sentence? :
"Please, have a look at the documents I've left in your office".
Thank you very much.
It depends on the timing.
The present perfect suggests that you have only just left them there and I haven't yet visited my office to see them.
Using the past tense would mean that I had seen them already and had chosen not to do anything about them so far.
It's the comma that's not necessary.