Soft, polite negative — equivalent to English 'not so great'. Chinese speakers often use 不太好 instead of 不好 to soften criticism. Note 不 changes from 4th tone to 2nd tone (bú) before 太 (tài, 4th tone).
grammar
不太 + adjective is a productive pattern: 不太贵 (not too expensive), 不太累 (not too tired), 不太对 (not quite right). Grammatically softer than 不 + adjective alone.
