[2604.03527] Explainable Model Routing for Agentic Workflows

Computer Science > Artificial Intelligence arXiv:2604.03527 (cs) [Submitted on 4 Apr 2026] Title:Explainable Model Routing for Agentic Workflows Authors:Mika Okamoto, Ansel Kaplan Erol, Mark Riedl View a PDF of the paper titled Explainable Model Routing for Agentic Workflows, by Mika Okamoto and 2 other authors View PDF HTML (experimental) Abstract:Modern agentic workflows decompose complex tasks into specialized subtasks and route them to diverse models to minimize cost without sacrificing quality. However, current routing architectures focus exclusively on performance optimization, leaving underlying trade-offs between model capability and cost unrecorded. Without clear rationale, developers cannot distinguish between intelligent efficiency -- using specialized models for appropriate tasks -- and latent failures caused by budget-driven model selection. We present Topaz, a framework that introduces formal auditability to agentic routing. Topaz replaces silent model assignments with an inherently interpretable router that incorporates three components: (i) skill-based profiling that synthesizes performance across diverse benchmarks into granular capability profiles (ii) fully traceable routing algorithms that utilize budget-based and multi-objective optimization to produce clear traces of how skill-match scores were weighed against costs, and (iii) developer-facing explanations that translate these traces into natural language, allowing users to audit system logic and iter...