RACC: Coupling Disagreement Routing with Receiver-Conditioned Messages under Bit Caps

A scarce multi-agent channel must choose both which receiver warrants a packet and what receiver-specific information that packet should contain. Receiver-Aware Coupled Communication (RACC) makes these choices from one sender-side receiver prediction: a thresholded forward KL between sender and predicted-receiver policies activates a directed edge, while the predicted receiver state and identity condition its binary $B$-bit message. On three hard SMAC maps and three packet widths, RACC exceeds BVME in all nine cells by 1.4–3.6 win-rate points under common widths; after independently matching mean charged payload bits, the gains remain 1.0–3.0 points and every paired interval excludes zero. Traffic-matched interventions expose the contribution of each connection: replacing discrepancy routing with a random gate loses $3.8[2.4,5.1]$ pooled tactical points, sharing one sender payload across receivers loses $4.8[3.2,6.3]$, and shuffling receiver identities loses $5.5[3.9,7.1]$. At $B=32$, RACC reaches 75.4%, 65.1%, and 90.8% SMAC win rate, 3.2–4.8 points above an encoder-, quantizer-, and width-matched always-send control, and leads every evaluated communication baseline in two- through five-player Hanabi. On held-out SMACv2 scenarios spanning 5, 8, and 11 agents, two graph densities, and three packet widths, it averages $3.7[2.5,4.8]$ points above BVME. Receiver prediction can therefore serve as a shared computational interface between packet allocation and personalized content when asymmetric information makes directed bits consequential.