Clinical practice guidelines (CPGs) are viewed by many people with interests in health care as valuable tools for reducing practice variations that undermine patient outcomes and increase medical costs. However, guidelines themselves vary in quality. Assessment tools generally base quality measures on strength of guidelines' evidence base, but particularly for newly emerging applications of ultrasound, standards for measuring guideline quality are controversial. The validity of a guideline is considered likely when strong research-based evidence supports its recommendations, but for newer medical procedures such as emerging ultrasound applications, available evidence is sparse. Existing assessment tools must be modified if they are effectively to measure the validity of these guidelines built on immature evidence. Focusing on ways document drafting affects CPG validity, this study rated six guidelines using the Appraisal of Guidelines Research and Evaluation (AGREE) tool which was customized according to categories of guideline purposes and their differing features of validity. Fine-tuning AGREE in this way may create a more consistent, informative method of evaluating guidelines for emerging applications, and standards established in such an instrument may be useful as a template during the guideline development process. Results from my analyses illuminate several common omissions that weakened documents. Most guidelines did not describe an updating procedure or identify areas for future research, but results also highlighted some highly effective techniques for building validity. Notable examples include providing full credentials for expert drafters, and embedding statement references directly in the text. From the results of the analysis, I conclude that, although the adapted assessment tool I used needs additional adjustment, it may refine analysis of guidelines for emerging ultrasound guidelines and conversely serve as a useful tool during their development process.