Pull Metadata about Validation & Workflow rules using API

Hi,

While using the metadata service as below -

curl -H "Authorization: Session abcd" https://api2.clarizen.com/v2.0/services/metadata/describeEntities?typeNames=Data

Only all the field columns metadata is pulled. How can i also pull the metadata for Validation & Workflow rules and custom actions that have been setup on the Data or any other entity type ?