So you see, the response requested is indicated in the very form and name of the document itself. The Letter of Intent has no established place in International trade law. Where they are used _ rarely _ is in some small niche internal markets and trades. The RFQ, Request for Quotation, a standard protocol in the business world, is what most brokers actually want when they err in using an LOI.
Among Internet based brokers and agents the LOI is commonly advanced as a leading inquiry document. This protocol is utterly incorrect, and misuse of the LOI is often seen by experienced Exporters as a mark of an amateur. Letters of Intent are not standard international business documents, though they do legitimately pop up rarely, much less often than most brokers believe.