Yes, ATTENTIONS is a Scrabble word!

Letter values in Scrabble US: A 1, T 1, T 1, E 1, N 1, T 1, I 1, O 1, N 1, S 1.

Is it a valid word?

ATTENTIONS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the process whereby a person concentrates on some features of the environment to the (relative) exclusion of others
the work of providing treatment for or attending to someone or something
a general interest that leads people to want to know more
a courteous act indicating affection
the faculty or power of mental concentration
a motionless erect stance with arms at the sides and feet together; assumed by military personnel during drill or review