In that example I don't care about the parents without children, but I guess the lighter way to do that is to add the having clause like:

Select count(tablechild.someid) as itemcount, tableparent.description ;
	from tableparent ;
		left outer join tablechild ;
			on tablechild.someid = tableparent.someid ;
	group by tableparent.someid,tableparent.description
                having itemcount>0