How do I know if my agency positioning is focused enough?

Use the elevator pitch test. What works is a pitch where you can say in a few seconds what you do and people want it. If you have to explain what you do, it is too vague, which is a common problem with AI businesses ("we do AI for everything").

People want results, so lead with the result your solution delivers. A broad position such as an AI business partner can still work if you can say clearly what results it delivers.