Would it be possible to add under the Commit-comment field a dropdown or list which shows the data of a TFS-"Team Query"?
We have implemented a "CheckIn"-Query which shows the developer his open Tasks/Bugs/... so that he can just select out of this list while checking in the pending changes.
Entering the IDs manually is annoying and most of the developers don't do it because they have to go to the TFS first, catch the ID go back to SQL Server Management Studio and write the text.
In VisualStudio this works fine - the developers just change the tab and select the item(s) and commit the changes on the "pending changes" tab.

I think the most elegant solution would be if you present the possibility to decide if the checkin will be done on TFS directly
or only on the corresponding local TFS-files. If it happens only on the local files you could see them in Visual Studio and use the
functionality there - and more than that you could check in the SQL-Code together with the VisualStudio code at once.
But then you would have to make sure that you don't loose the change-history in order to be able to deploy the changes from Development to Acceptance and Production SQL-Servers.