I know this post is quite old, but I was just doing some research into this very subject and found quite a few tools. I have not used any of them, so I can not speak to their performance. I am just posting these here to help out the next guy as accumulating this list was rather tedious.

- http://www.ubitsoft.com/products/sqlenlight/

- https://www.devart.com/dbforge/sql/studio/sql-analyzer.html

- https://www.dbbest.com/products/t-sql-analyzer/

- http://sqlcop.lessthandot.com/- no custom tests.

- http://sqlcodeguard.com/- no custom tests.

- http://www.manduka.tech/#/home - very limited tests for t-sql. not sure if custom tests can be made

- https://github.com/chrisoldwood/SS-Cop- pure t-sql. interesting from a theoretical point of view. extremely limited