After searching it a bit, amiNes like to react with C=O bonds, forming -N=C- +H2O while amiDes react with -OH bonds forming -NH-C- +H2O. So CHZ with formic acid will for sure react with the amine forming O=C-(NH-NH2)-(NH-N=CH-OH). Now the -OH group will not react with the second amiNe group (-NH3). If it will, it will react with the amiDe (-NH-) group closing the ring, forming amino-triazol-one. Now the point is, how reactive the -NH group going to be with the -OH group ? In the case of semicarbazide, the amiDe group is a primary amiDe, easily reacting with the -OH group forming -NH-C- and clozing the ring, but in the case of CHZ, one H is replaced with the amiNe group, making the amiDe less reactive right ?