One of the principles learned during the development of the MISRA guidelines has been the primary importance of being able to enforce rules with static analysis tools. It has been amply demonstrated, that without the ability to implement automatic enforcement, coding rules are of marginal value. The market for tools, which provide enforcement, has grown in parallel with the adoption of MISRA Coding Guidelines. Many tools are now available claiming to provide enforcement of MISRA rules. This paper discusses the reasons why such claims are either a misconception or a deception and outlines some of the principles which should be understood when assessing tool performance.