This article examines how to assess the social effectiveness of inclusive library services in the context of social transformation. It aims to develop a conceptual evaluation model and an indicator matrix, proposed for empirical testing, that connect service accessibility with broader social outcomes. The study is not a systematic review or meta-analysis; it uses a targeted critical literature review and conceptual synthesis. The evidence base comprises publications from 2000 to 2026 on librarianship, social inclusion, social capital, digital inequality, and impact assessment, together with international standards and official and empirical materials relevant to Kazakhstan. The final analytical corpus contains 70 sources. Social effectiveness is distinguished from operational efficiency and service volume and organized into five levels: institutional readiness and accessibility; inclusive use and participation in service co-design; social connection and belonging; capabilities and social integration; and public impact and resilience. The article proposes normalizing indicators to a 0-100 scale, treating mandatory accessibility requirements as non-compensatory thresholds, and initially reporting results as a multidimensional dashboard. Organizational indicators should be validated as formative measures, whereas multi-item scales of trust, safety, and belonging should be tested as respondent-level reflective constructs. The model is intended for contextual adaptation and pilot testing in Kazakhstan's libraries. Its main limitation is the absence of empirical validation.