May negatively regulate the activity of cGMP-dependent protein kinase egl-4 which in turn controls body size. a nucleoside 3',5'-cyclic phosphate + H2O = a nucleoside 5'-phosphate + H(+) Binds 2 divalent metal cations per subunit. Site 1 may preferentially bind zinc ions, while site 2 has a preference for magnesium and/or manganese ions. Reduced body size and an egg-laying constitutive phenotype. Belongs to the cyclic nucleotide phosphodiesterase family.