pattern - What is an Uptight™ Word?

_{This is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles.}

If a word conforms to a special rule, I call it an Uptight Word™.
Composed Words™ are not Uptight Words™.

Use the following examples below to find the rule.

Here they are in a CSV format:

UPTIGHT WORDS™,COMPOSED WORDS™
ABASHED,ANGRY
BRAZEN,CALM
CRAZY,COMPOSED
EXCITED,COOL

EASY,FURIOUS
FIERCE,HALCYON
HUSHED,MAD
MILD,NERVOUS
PLACID,RELAXED
ROUSED,RUFFLED
SEDATE,SERENE
TENSE,UNCOOL
UPTIGHT,VIOLENT
WORRIED,WILD

Answer

An Uptight Word™ is a word ...

... whose Scrabble score is a prime number.

Conversely, a Composed Word™ ...

... has a non-prime or composite Scrabble score: The score is composed of several factors.

Evidence section:

ABASHED: 13 ANGRY: 9
BRAZEN: 17 CALM: 8
CRAZY: 19 COMPOSED: 15
EXCITED: 17 COOL: 6
EASY: 7 FURIOUS: 10
FIERCE: 11 HALCYON: 15
HUSHED: 13 MAD: 6
MILD: 7 NERVOUS: 10
PLACID: 11 RELAXED: 15

ROUSED: 7 RUFFLED: 14
SEDATE: 7 SERENE: 6
TENSE: 5 UNCOOL: 8
UPTIGHT: 13 VIOLENT: 10
WORRIED: 11 WILD: 8