This critical discussion paper argues that the development of nurse-sensitive metrics in general practice is not simply a technical task of selecting indicators, but an ethical and methodological process through which nursing contribution becomes known, named and represented. Although health systems increasingly prioritise measurement, accountability and performance data, important dimensions of nursing practice remain poorly captured, particularly in community and primary care contexts. In general practice, nursing care is characterised by generalist, relational, preventive and cumulative forms of care, making the direct transfer of metrics developed outside this context problematic. General practice nurses represent a substantial workforce, yet their contribution remains only partially visible within existing healthcare data systems. This paper advances a Responsible Action Research approach to developing nurse-sensitive metrics grounded in everyday practice. Drawing on Action Research, implemented through Appreciative Inquiry and informed by the Quality Action Research Checklist, the paper considers how collaborative inquiry can support general practice nurses to articulate dimensions of nursing quality that may otherwise remain tacit. Inclusion of perspectives from general practitioners, patients and practice administrators further situates this inquiry within the broader ecology of care. The paper argues that responsible metric development requires attention not only to what is eventually measured, but to the transparency, reflexivity and accountability of the process through which potential indicators are generated. By reframing metric development as a practice-engaged process of knowledge generation, it offers a methodological contribution to debates on how nursing work can be made visible without reducing its complexity.