While traditional psychometric evaluations determine the quality of assessment tools, it is also important to understand how their clinical usefulness develops in practice. This study investigates how psychodynamic psychotherapists in the early stages of learning the Structured Interview of Personality Organization - Revised (STIPO-R) experience and integrate it into practice, using a constructivist-interpretivist perspective to examine this process. Seven psychotherapists from the Polish STIPO-R validation study took part in semi-structured interviews exploring their early use of the tool. Data were analyzed using reflexive thematic analysis with team discussions, detailed coding, and reflexive strategies to ensure trustworthiness. Six themes were developed in the analysis: Psychotherapists tend to (a) modify and personalize the STIPO-R; (b) identify what the STIPO-R can and cannot do in real practice; (c) navigate relational dynamics while administering the STIPO-R; (d) shape their understanding of patient functioning through observation and interpretation of responses; (e) reflect on the significance of embedding the STIPO-R in object relations theory; and (f) struggle with some elements of the STIPO-R during the diagnostic process. Our findings show how clinical utility is co-constructed and highlight key aspects to observe-an insight valuable for training. We discuss implications for examining this shaping process for other clinical tools as well.