What should the salesperson read before replying?
Read the original request and any replies from colleagues. Identify what the buyer wants to decide: product fit, implementation effort, price, availability or a meeting. Separate that question from your own desire to book a demo.
Check who owns the conversation. If another teammate has promised a response, coordinate internally before sending a second introduction. A change of owner should not make the buyer explain the project again.
The lead qualification guide helps choose questions that affect the next step. Leave details for later when they do not change the answer you owe now.