ScoutCrew: Coordinating Multi-View Exploration and Evidence Synthesis for Spatial Reasoning

Spatial reasoning often requires information that is not fully visible in the supplied images. Additional viewpoints can reveal useful cues, but their value depends on what they show and how their findings are combined. We present SCOUTCREW, a coordinated multi-agent framework that plans observations together with their roles in the inference. A Coordinator assigns observation subtasks and constructs an Investigator Relation Graph (IRG). Complement relations connect tasks that supply different premises, while CrossCheck relations connect tasks that examine the same spatial proposition. Investigators execute their plans through generative view synthesis. They then exchange reports and observation context along the IRG to resolve missing information and revise their findings. An Analyst assembles the revised reports into a chain of evidence (CoE), connecting observations and intermediate conclusions to the final answer. ScoutCrew improves overall accuracy across all evaluated backbones on SAT-Real and multi-image MMSI-Bench. Gains over direct inference reach up to 14.0 and 9.5 percentage points, respectively. These results support coordinating observation acquisition and evidence composition for spatial reasoning from limited views.