The default hammer for that nail is generally Params::Validate, from what I've seen. Just from looking at the POD, its template syntax also seems to be more expressive than that of Params::Check. As well, Params::Validate is older, but has had fewer releases and the last one is a while back, with no reported bugs (but a few open wishlist items); knowing its authors, I'd say that means it's stable rather than unmaintained. OTOH, Params::Check is maintained by the same guy who maintains CPANPLUS, so name alone is no indication here.