Peer feedback is regarded as playing a vital role in fostering preservice teachers' noticing and reasoning skills during technology integration. However, novices in particular (e.g., pre-service teachers) tend to provide rather superficial feedback, which does not necessarily contribute to professional development. Against this background, we developed an online video-annotation tool, "LiveFeedback"+, which allows for providing peer feedback on the quality of technology integration during microteachings in a fine-grained manner. Applying a design-based research approach (2 design cycles, N = 42 pre-service teachers, quasi-experimental interrupted time-series design), we investigated whether the addition of prompts (Cycle 1) and strategy instruction combined with prompts (Cycle 2) contributed to the quality of peer feedback. Contrary to our predictions, piecewise regressions demonstrated that pre-service teachers provided more feedback comments with superficial praise and fewer feedback comments with substantial problem identification and solutions when prompts were available. However, when pre-service teachers were explicitly instructed in strategy use, the reasoning during peer feedback could be enhanced to some extent, as pre-service teachers provided less praise and more problem diagnosis in feedback comments when strategy instruction was available. These findings suggest that the addition of strategy instruction that explicitly models adequate feedback strategies based on prompts can help overcome mediation deficits during peer feedback in technology-based settings.