Multi-turn tool-use scenario.
Tools involved: MessageAPI
TravelAPI

User requests (one per turn):
user: I need you to verify my travel documents before I embark on this journey. Confirm if my personal details match the required criteria. Once all checks are done, I'll proceed. For reference, my birthdate is February 14th 1962 ans passport number is P87654321, my first name is Michael and last name is Smith
user: I'm considering flying but need to know the cost of traveling from here. Let's identify the nearest airport to Chicago first, then we'll continue to check airfare from there to Los Angeles for Aug 10th 2024.
user: Now that I have the flight cost, please set a budget of $1500 for my trip using my account token 'token_ABC123XYZ' to make sure everything's in order.
user: Book this flight for me, please. I am flexible with travel classes but would prefer to keep it within my budget. I'll promptly handle the payment using my saved card details with id 'card1'.
user: If any details are overlooked, please retrieve any recent messages I sent concerning this trip.

Expected function call sequence:
TravelAPI.verify_traveler_information
TravelAPI.get_nearest_airport_by_city
TravelAPI.get_flight_cost
TravelAPI.set_budget_limit
TravelAPI.book_flight
MessageAPI.send_message
MessageAPI.view_messages_received