Yes, the definition of genocide is satisfactory, because we all know what genocide is. There is clarity on the problem of genocide. Usually when there are disagreements on the issue of whether something is genocide, the issue has more to do with the underlying political issue than it does with whether people are being inhumanely killed.
The definition of Genocide is satisfactory for the most part. It could be improved in a few more places and be more descriptive in terms of ours history and how we can avoid it. Other than that it does a good job of explaining how Genocide is the complete destruciton of a people and culture.