Routing policies for multi-model systems are evaluated almost exclusively on task accuracy and inference cost. We argue that two properties, orthogonal to performance, determine whether routing is meaningful. First, the society of actors must be behaviourally differentiated: if all actors respond identically, routing is vacuous. Second, the routing policy must be stable: surface-form variants of a query should be assigned to the same actor. High task accuracy is compatible with violating both properties, since a router can operate over a redundant society or assign queries inconsistently, preventing specialisation regardless of performance. We adapt Hierarchic Social Entropy (HSE) to language-model societies and introduce a perturbation-based robustness metric to diagnose these failure modes. Applied to EmbedLLM and RouterBench, we find that HSE exhibits strong diminishing returns, suggesting that a curated subset of fewer than ten agents recovers most available diversity in a large pool -- a practical coreset heuristic for society design. We further find that KNN routers gain accuracy from specialist societies but collapse in robustness under perturbation, while prompted routing remains stable across all perturbation types -- illustrating that accuracy and meaningfulness can sharply diverge.
VDAR-Router is proposed, a difficulty-aware retrieval-based routing framework for training-free LLM routing that consistently achieves better cost-performance trade-offs than existing baselines and helps retrieve more relevant examples and supports more reliable routing decisions.
Yu-Chien Tang, Jun-Chen Hung, Wen-Chih Peng et al.· 0 citations
Very Large Scale Integration (VLSI) global routing is an NP-hard combinatorial optimization problem requiring signal net assignment across capacity-constrained 3D grids while minimizing congestion, wirelength, and via transitions. Because traditional heuristics rely on static penalty schedules that fail on complex congestion topologies, we present AlphaRoute: a multi-objective adaptive search framework reformulating rip-up and reroute (R&R) into a dynamic optimization system. We introduce SHAP-based overflow decomposition to isolate per-net congestion, driving targeted subgraph extraction via 3D Dijkstra maze routing and an adaptive PathFinder policy. Crucially, AlphaRoute employs Large Language Models (LLMs) as semantic policy optimizers. Bounded by a deterministic knowledge graph, the LLMs interpret congestion metrics to dynamically adjust penalty parameters. Evaluated on ISPD 2025 benchmarks, AlphaRoute reduces overflow by 98.6% on MEMPOOL. On the constrained ARIANE design, we achieve an overflow of 146,109 (a 29.8x reduction in overflow over the state of the art), yielding a penalized score of S_orig = 0.0538 versus the State-of-the-art (SOTA) 1.780. These results demonstrate that superior algorithmic search geometry can overcome the latency of interpreted Python implementations.
Kabir Murjani, Mishri Bhavsar, Manish I. Patel et al.· 0 citations
TRACE-Router is presented, a task-level routing framework that aligns routing with the unit of supervision, and learns routing policies that adapt to the workload while avoiding explicit task-complexity estimation.
Ritik Raj, Souvik Kundu, Sarbartha Banerjee et al.· 1 citation
This work introduces SWE-Router, a value-based temporal approach that lets a cheap model run for a few exploratory turns and reads the resulting partial trajectory before deciding whether to continue cheaply or to escalate to an expensive model, and provides a Bayes-optimality theorem showing that conditioning on the partial trajectory never harms routing and is strictly better whenever exploration is informative.
Seongho Son, Sangwoong Yoon, Jiahua Tang et al.· 4 citations
Empirical results on RouterBench and SWE-Bench demonstrate that WR-Offline surpasses existing baselines in performance under a fixed budget and adheres more closely to budget constraints, and WR-Online achieves comparable performance to the baselines, while using substantially less exploration data.
LLM-Advisor is introduced, an open-source, adaptive framework designed for intelligent query categorization, dynamic model evaluation, and constraint-aware request routing across heterogeneous multi-LLM pools that achieves a 42% reduction in overall inference expenditure and a 35% decrease in average response latency.
Harshil Lodhiya· International Journal of Res...· 0 citations