Updating external content type for SharePoint 2010 Business Connectivity Service

Our client submitted a request to update their existing External Content Type used for BCS. The request was so simple: rename Address field into Department and add 1 extra field. I thought this should be easy.

So I updated the employee model and redeployed the solution. But for some reason the changes didn’t get reflected in the content type. I have tried everything from resetting IIS, clean solution, rebuild solution, even copy and paste the dll directly to the GAC without any result.

After further investigation I found out that the type descriptor (which you can see from BDC explorer or by opening the bdcm file in notepad) are not automatically updated.
So that is the lesson, the type descriptors needs to be updated manually.