H1b visa job description document

Hi Saurabh,

My company is going to file a petition for me this year. My question is what is the importance of the Job description document and proposed job duties document in this process. Is that something that has to be prepared by an attorney or a professional? Or is it something that just needs to list the responsibilities of an individual and can be prepared by me myself. Ideally who should be preparing these documents?

Also, what is the criteria for an H1b application to be rejected?

Is the rejection rate higher when the petition is filed or when the visa interview happens?

I have had issues with my business visa previously? Should those be of any concern while h1b is getting filed?