In Texas our law requires that all contracts are submitted, whether good or bad. There is a form that the agent can present with any offer -Notice of Presentation of Earnest Money Contract - that the seller signs off on showing that they were presented the offer. It is more commonplace now to be asked by other agents if there is an offer on the table currently so the agent will know. It is the listing agent's duty to inform the buyer's agent that there is another offer on the table if that is the case. It is "courtesy" to invite "BEST" offers to be submitted. I say BEST because price in this market isn't always the better of the two, especially if a fully approved buyer is writing vs a buyer that doesn't even have a lender qualification letter. I'd recommend my sellers anyday to seriously consider an approved buyer to counter/negotiate with.
Hope this helps - great question by the way!