What does it mean that AI agents buy B2B?

AI agents compare suppliers, check the contract, place the order and settle the invoice on behalf of a business. Gartner forecasts 90% of B2B buying goes through agents by 2028, over $15 trillion. My call: by 2030, routine, rules-based buying is agent-to-agent by default. People keep the strategic deals, set the rules and approve the exceptions.