fully awake and ready to act, speak etc

attentive, lively

moving, doing things, quickly and easily

dexterous, smart

quick at noticing things

alert, watchful

acting, done, sent, given, without delay; to be the reason causing (a person) to do something; to follow the text of a play and tell (an actor) what to say if he or she forgets

early, responsive

a person who prompts

early, responsive

without sleep

insomniac, restless

keeping careful watch

careful, watchful

careful about possible danger or trouble

careful, cautious