No - they're different. Here only unsatisfactory
is correct. Satisfactory/Unsatisfactory
means that something does or doesn't meet a standard, probably set by other people than the person involved. So here, it's the company which has decided the performance standard, and they're saying that this person's performance doesn't met it - in other words isn't good enough. Here are some examples - you can see that the meaning is always " It's not good enough":
--If the order is unsatisfactory, return unworn/unused within 7 days, and
--But can't we do something about this unsatisfactory situation?
--It is a thoroughly unsatisfactory piece concerning a literary agent who
--Mr Nelson Mandela, has also rejected as unsatisfactory the proposed ministerial investigation.
--the Ministry of Defence's complacent and unsatisfactory response to the sinking. Satisfying/Unsatisfying
is different. It means that the person involved does or doesn't get satisfaction from something. Here are some examples :
--binge-eating may be provoked by a new or unsatisfying job,
--they fear rejection, and put up with an unsatisfying relationship because they
-- of a dating agency were put to sleep after unsatisfying pilot episodes.
--with the evidence about the dramatically unsatisfying, but probable cause of his death
--and rioting - is caused as much by people's unsatisfying home lives as by lack of work.
So - someone might find a job unsatisfying. But other people would find their performance unsatisfactory.
I hope you find this a satisfactory response ?