According to the New Schaff-Herzog Encyclopedia of Religious Knowledge, the Kestoi "appears to have been intended as a sort of encyclopedia of the material sciences with the cognate mathematical and technical branches, but to have contained a large proportion of merely curious, trifling, or miraculous matters, on which account the authorship of Julius has been questioned.
Menurut New Schaff-Herzog Encyclopedia of Religious Knowledge, Kestoi "tampaknya dimaksudkan sebagai semacam ensiklopedia sains material dengan cabang-cabang matematika dan teknik kognitis, tetapi memuat bagian besar hal-hal yang sekadar untuk ingin tahu, remeh atau ajaib, yang membuat Julius sebagai pengarang dipertanyakan.