package Person;
use Moo;
use Types::Standard 'Int';
 
has name => (is => 'rw');
has age  => (is => 'rw', isa => Int );
 
1;

##</code><code>##

perl -I. 1223262.pl
Foo
22
Value "young" did not pass type constraint "Int" (in $self->{"age"}) at 1223262.pl line 9
    "Int" is a subtype of "Num"
    "Num" is a subtype of "LaxNum"
    Value "young" did not pass type constraint "LaxNum" (in $self->{"age"})
    "LaxNum" is defined as: (defined($_) && !ref($_) && Scalar::Util::looks_like_number($_))