I don't have a specific recommendation (I could just give out names of tools that seem to match your needs but I can't really say I've used any), but in your place I'd reconsider your last requirement of "no connection to the DB".

In my view the best docs are the ones that take the least effort to keep up-to-date. Consider a tool that's able to dynamically list and extract schemas from your existing tables and generate a nice HTML or diagram that can be used as a quick and up-to-date reference. That will require little or zero maintenance compared to a manual diagramming tool. So I'd start looking there.

Depending on the project and usage I'd also consider exposing the database through an API. This makes documentation much easier too, as there are tools to auto generate API docs and you'll decouple your DB schema + access from its usage, which has its own benefits.

duh

that assumes you already have a credit line, as one should.

we don't need money, just credit. It's not like we'll need to pay it off.

deleted by creator

man touch

possibly never going to happen