A deal, whether in writing or orally, is not to be considered lightly, because you fully expect to keep your end of the bargain. Three things to consider before saying, "yes":
What happens now: Who owes who what? What, precisely, does each side promise to do, and what does each side get? It can't hurt to write this out in English and add it to the agreement, just to be sure you both agree.
What happens if things don't work out: If you don't do what you say you'll do, what happens? If the other person can't pay or can't deliver, or wants to walk away, then what? When you leave yourself (and the other person) an out, you're almost certainly investing in a better future, because you know in advance what the options are.
What happens if things do work out: If everyone's wildest dreams come true, then what? Does that person who gave you three days of advice end up owning half your gourmet foods business that you've worked on for twenty years? Describe the hypotheticals, and plan them out together, because today's hypothetical is tomorrow's unfair reality.
The fine print is there for a reason, and if you don't like it or can't live with it, cross it out or walk away. There's no better time than this very moment to be clear, to be honest and to have a difficult conversation.