In agile software development contexts, the definition and consistent interpretation of cybersecurity requirements remain a challenge, especially when such requirements are expressed through user stories with varying levels of detail and clarity. The lack of technical and architectural context can compromise the uniform identification of security requirements throughout the development process. This study presents an analysis of the application of cybersecurity requirements from the OWASP ASVS standard to 66 user stories, conducted by four distinct analysts. The Agile Security Framework (ASF) tool was used to annotate the requirements, and Python scripts were employed for data processing. The study evaluated the frequency, distribution, and convergence of 1,634 security requirement annotations. The results indicate a significant predominance of category V5 (Validation, Sanitization, and Encoding), accounting for 51.5% of the annotations, followed by V3 (Session Management) with 16.9% and V2 (Authentication) with 8.4%. The analysis revealed that, while satisfactory convergence exists in user stories with a clear scope, such as those related to authentication, textual ambiguity and the absence of architectural context in more vague stories lead to significant interpretative divergences among analysts. It is concluded that the textual clarity of user stories is a critical factor for consistency in the identification of security requirements.