That needs to be explained somewhere obvious. On the market page it only tells me the app is incompatible with my device, giving me no clue what to get that would run it (except for the OS versions, which my device satisfied).
We considered publishing a list of minimum requirements but we encountered phones that for whatever reason wouldn't work even though the hardware met the minimum requirements. For example, the Nexus One and HTC Evo both had low frame rates despite adequate hardware.