This paper describes the development of tools for a semi-automated process for validation of treebank annotation at various levels. Consistency in treebank annotation is a must for making data as error-free as possible and for providing quality assurance. The tool is aimed at ensuring consistency and to make manual validation cost effective. We discuss a rule based and a hybrid approach by which a high-recall system can be used to identify errors in the treebank. We report some results of using the tool on a sample of data extracted from a Hindi treebank.