Is realy The use of UML for document software ?

recently I have The challenge to design a little chat System.. betwen Watson IBM , dynamoDB anda React as front end.my partners in Works wants put her fingers on Code ASAP, I think that an a Architecture Must be performed on paper and pencil(Is easier a rollback in paper than servers), for that I Saw The 4+1 methodology.. that Is recomended to work thogether with UML, in some times I think that documentation could be harmfull that The Application. ... I will appreciate your comments :) about it.