I'm not too familiar with The Death Note, but the premise remains the same....causing the death of a being via the transcription of its name...actually, it began as a thought exercise of what'd happen if Santa Claus, or Sinterklaas, got his hands on something equivalent and starting trimming his 'Naughty n Nice' list.

The Book of Death is intended as an epic artifact, and is able to snuff out the existence of any being whose name is so written across the boundaries of realities and planes.
It rejects made-up names because it 'knows' instantly those names are false; this was also a fail-safe to ensure that individuals possessing said artifact do not prolong their possession by giving the Book misleading information and thus avoid their own demise.