Ask HN: How do you document your Data Models?

When documenting my last project I came to the realization that all projects I have worked on have a very poor documentation of their data model. I believe that this leads to longer onboarding time and a lot of newscommer mistakes in the project (such adding new properties for something that exists somewhere else). Generally the data model is documented in the database / ORM, but it generally describe the physical representation of the data in the database (name is a Varchar(128)) but not how/for what such data are to be use (which is sometime complicate to understand on old project where knowledge has been lost and when naming is not consistent/explicit).

It seems that recent ORM that allow you to describe your DB schema as code (like Prisma) allow you to add ‘comments’ on your Data model, but I feel it’s not enough.

I have look at the data modeling tooling but haven’t found satisfying solutions.

I missing something? How do you document your app data model?