The bool field type should be represented as an integer field in your database. Usually schema creators allow you to choose BOOLEAN which resolves to something like TINYINT(1). This field will work as long as you can put integer 1s and 0s in your database field.
'is_good' => array(
'type' => 'bool',
'title' => 'Is Good',
)
In the edit form, an admin user will be presented with a checkbox that looks like this:
A bool field type can be used in the filters option. When used as a filter, it will give the admin user the option to either choose true, false, or all.
