# Executive Summary # Executive Summary Agentic RAG systems combine: ● Reasoning models ● Retrieval systems ● Tool use (increasingly via MCP) ● Memory (short-term, long-term, and now tiered/benchmarked) ● Workflow orchestration ● Governance controls ● A harness layer that governs all of the above The goal is not maximum autonomy. The goal is reliable, auditable, policy-aligned autonomous execution. Modern production systems optimize for: ● Accuracy ● Cost efficiency ● Safety ● Explainability ● Human oversight ● Operational resilience NEW IN 2026 The single biggest framing shift: the model is now understood as the smallest part of the system. Practitioners increasingly describe production agents with the equation Agent = Model + Harness, where the harness — not the model — determines reliability, and benchmarks such as Harness-Bench show that swapping the harness around an identical model pool can move task-success scores by over 20 points.