BiGate: Bidirectional Verification-Guided Selective Communication for Multi-Agent Reasoning

Multi-agent reasoning can exploit complementary capabilities across heterogeneous language models, but indiscriminate full-reasoning exchange increases inference cost and exposes revision contexts to unnecessary or erroneous peer information. We propose BiGate, a bidirectional verification-guided selective communication mechanism. For each agent pair, BiGate forms a response-local ternary verification relation from the two directional judgments. The Sender Need Gate uses the sender’s judgment of the receiver to decide whether communication is needed and whether feedback is supplementary or corrective, while the Receiver Scope Gate uses the reverse judgment to control whether the sender’s full reasoning enters the receiver’s revision context. Their joint mapping yields dynamic directed typed communication, while two-stage context isolation prevents verification-time peer reasoning from carrying into revision except through gated messages. Across five reasoning benchmarks and three heterogeneous base models, BiGate achieves 73.90% macro-average accuracy, 2.30 percentage points above the strongest collaborative baseline, and uses the fewest model calls and Response Rounds among the evaluated multi-agent methods. Ablations and behavioral analyses support the gates’ distinct roles and show task-varying communication with restricted full-reasoning admission under persistent error.