apparently i should cut it the other way and it was a little tough
Cutting across the grain will tend to moderate any toughness. Brisket needs a high temperature to break down the tough fibers. I usually take mine to an internal temp of over 190°. (195° is the target but I can get impatient.
) That's done in a WSM or mini-WSM over ten or more hours. You can probably do that in a kettle as well but temperature control is probably going to be more work. I don't know how well higher temp/shorter time would work as I have not tried it.
Of course a little tough takes nothing away from the flavor.