Property damage versus personal injury
This distinction matters more than almost anything else here. If you or anyone involved was physically hurt, that's a personal injury claim — a different legal category, usually worth more than $12,500, and generally handled in regular civil court, often with an attorney. Small claims is built for the narrower, more common situation: nobody was hurt, but a bumper, a fender, or a windshield needs to be paid for, and the other driver's insurance either denied the claim or never covered the full cost.
What actually proves the case
What you can actually claim
The repair cost is the core of it, but it isn't the whole picture — a rental car while yours was in the shop, towing and storage fees, and even an insurance deductible you paid out of pocket can usually be included. If the damage was significant enough to lower your car's resale value even after a good repair, that diminished value can sometimes be claimed too, though it typically needs its own documentation to support the number.
When insurance is already involved
If the other driver's insurer denied the claim or offered far less than your repair estimates, that denial letter or lowball offer is useful evidence — it shows you tried the direct route first. Small claims doesn't require you to have gone through insurance first, but doing so (and keeping the paper trail) tends to make the case easier to explain to a judge in a couple of minutes.