Add the tomatoes, red onion, parsley, and capers to a small bowl.
In a separate bowl, whisk together the olive oil, lemon juice, garlic, salt, and pepper.
Pour the dressing over the tomatoes and gently toss to coat evenly.
Taste and adjust the salt and pepper as needed.
Notes
Let it rest briefly. If time allows, let the salad sit for 10 to 15 minutes so the tomatoes release their juices and create a light, flavorful dressing.
Slice onions thinly. Very thin slices blend into the salad better and prevent overpowering bites.
Start light on the dressing. Add a small amount first, toss, and add more only if needed so the tomatoes stay fresh and balanced.