While supporting the "it depends" philosophy the previous respondents have suggested, I'd strongly recommend Method::Signatures (http://search.cpan.org/~barefoot/Method-Signatures-20160315/lib/Method/Signatures.pm). This allows you to set type constraints (http://search.cpan.org/~barefoot/Method-Signatures-20160315/lib/Method/Signatures.pm#Type_Constraints) and value constraints (next section) as well as its other benefits.

Regards,

John Davies