The guys at MS ADO.NET have released a tool that is amazing for diagramming your context EF Code-First. There is more to your EF model than just POCO classes — for example, an API that supports mapping — and the tool takes it into account.

Without further ado, this is an extension of VSE EF Power Tools (beta 2 at time of writing)
Read all about how to install and use it on the ADO.NET post-related blog.
Be warned, the chart is read-only, but what do you expect when the input for it will be your own code?
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