Is a 50-40-10 macro ratio (fat, protein, carbs) decent?
Depends on your goals, would help if you elaborated a little.
It's low carb - perfectly ok, I think, if you're aiming for weight loss and if you find that you function well on low carbs.
My body works well on around 50 g of carbs a day (my maintenance cals are 1800 - I am a woman, 140 pounds) I have been doing under 10% carbs, around 35-45% protein for almost three months, have lost 6% of bodyfat and gained a bit of muscle with intense heavy lifting. I think it's fairly sustainable for me. I probably wouldn't go higher than 15% of carbs because of a history of insulin resistance and what my trainer calls carb intolerance.