The problem with descriptivism in modern physics is that you say physical theory describes something independent, but you end up postulating the things that it describes as part of the description language, you do not provide any additional denotation for them. I.e. you claim that it describes the real stuff, but in fact it only describes the constants of its language. So the descriptive view forces anti-realism. But it seems your mereological reductionism is a form of realism.

I'm having trouble following your argument here. Could you clarify how descriptivism commits me to anti-realism?