Problem statement. Unintentional violations by a user of instructions for working with an information system, leading to information security threats (unintentional insider incidents), are a serious issue in the field of information security. The main cause of such violations is that, due to a certain psycho-emotional state of the user, a deviation in behavior occurs, and the user may make mistakes both in choosing and in working with system interface elements: for example, entering confidential data into "open" fields. The aim of this work is to describe a software tool for modeling, developed based on the author's system interface model and instructions. Research methods: computer modeling, software engineering, experiment. The result: in addition to the very fact of creating a software tool, its operability has been proven in terms of modeling the interface in an information system and instructions for working with it, as well as the visibility of the resulting graphical representation. The practical significance lies in the fact that this tool allows you to implement a method to counteract the deviation of user behavior by solving the optimization problem of clarifying instructions in terms of the specification of the description of interface elements; at the same time, this task is multi-criteria, since increasing the content of instructions leads to the opposite effect - complicating its perception by humans.