A problem that you may encounter when adding Managed Attributes is that you are unable to extend the Managed Attribute Description field beyond the 450 character limit, regardless of changes you make to the Database Schema or the ManagedAttributeExtended.hbm.xml.
Although you are not aware of the problem, you are probably exceeding the allowed size of a description within the database itself. The descriptions are capped at around 450 characters. These are stored in the extended columns of the spt_managed_attribute table. Part of the limitation of the size is due to the requirement for an index on these columns; many databases have an upper limit on the size of a column that can be indexed and that limit is capped at around 450 characters.
You can change the size of the Managed Entitlement descriptions using the ManagedAttributeExtended.hbm.xml file which can be found under the directory
by resetting an attribute to the appropriate length to allow for the rather large number of characters and then recreate your database to allow for this expanded schema attribute.
The better way to approach this is to modify the model for the descriptions.
This will allow you to take a second look at how you choose to present the descriptions within your data model. Logically, a 1500 character description for a single entitlement is problematic, as it would be very difficult to maintain, and complex to end-users to be required to read and review a 1500 character description of the Managed Attributes. Therefore, the better solution is likely to review how the model is being presented versus trying to alter the XML and database schema to try to add a burdensome description that would exceed the database's limit to index.