How to Distinguish between friendly flirting and real flirting?

I met this girl on tinder, she's amazing i asked her if she want to go out with me and she said yes and i always flirt with her and she kinda flirts back. But the problem is she's a dry texter and she sometimes seems to act uninterested. I always reply on her Instagram stories with flirtatious vibe and she flirts back but she conversation became dry quickly. We don't talk a lot and it's been a month that i'm in a some sort of loop. I reply, we flirt and boom conversation over. So my question is she interested or she's flirting back and talks to be polite and friendly?
How to Distinguish between friendly flirting and real flirting?
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