Arduino Networking protocol

I am designing an application on which an arduino board communicates with a server. I understand the first thing i need to do is to design a protocol , but am not really sure on how to go about it. The description of the functionality is shown below

Arduino will communicate with the server. When an RFID tag is placed on the Arduino, the Arduino must immediately initiate communication with the server, this will be done so as for the server to open its database , search for the given tag, and then classify it according to the priviledges within the server. i.e it will search through the tables within the database for the given tag, and when found, it must Identify the table from which the tag exists and give necessary permissions to the Arduino. The server will then send a response to the Arduino board which then closes connection. so i have come up with the protocol as

 1)Initiation of communication 2)If Communication is successful, Arduino sends the received tag to the server and if  not a signal is shown on the Arduino to state that connection was not feasible. 3)Server receives the tag, and uses it to verify priviledges and then  sends a yes or no to the Arduino  4)Arduino closes communication

I am not sure if i can conclude this to be my protocol or in protocol design i need further refinement. Any help will be truly appreciated