Abstract
The natural language generating is an exciting research topic. An agent that may speak is a dream for all artificial intelligent researchers. There are two domains for NLG. One is the grammar of the message and the other is the content of the message. In this paper, we will discuss some problem when the content of the message is involved in an executable plan. The difference of knowledge and believe between two agents may lead the conversation to a failure situation. We’ll discuss how the failure occurs and how to avoid it.