When I’m creating new characters I sometimes refer to Linda Goodman’s Sun Signs book, written in 1968. Although it's over forty years old I don't think anything's changed over the years. It's a fascinating book and this is some of what she has to say about Sagittarians:
Sagittarians never do things half way.
Sagittarians may sometimes seem both casual and careless but don’t let that mislead you.
Sagittarians can be bold. You’ll be aghast at their forthright statements.
Sagittarians are curious. He’ll never be satisfied with simply being given instructions, he’ll want to know reasons and why.
Dishonesty is not one of their weaknesses, neither is tact.
Sagittarians sometimes have outbursts of temper, but it never lasts long enough to burn.
Incidentally, my husband is a Sagittarian and so many of these things are true to his nature.
Is there anything more you would add?