I would agree with Chris Date on that. Yes, it's up-front work, but in my opinion everything that can be validated in a DB should be.

I love arguing this one with devs, so much 'agile' nonsense sometimes. 😀 "Creating validation in the database is a violation of the DRY principal"

One dev (few years ago) with that initial attitude came back a couple weeks later: "I checked the DB, found that I had a bug in the app which was letting incorrect values through. I've fixed the bug and added some DB validations."

Description fields, like comment fields are hard, they are free text. I suspect your problem was more a data type mismatch than a validation issue per se.