In-Context Prompting Obsoletes Agent Orchestration for Procedural Tasks

arXiv:2604.27891v2 Announce Type: replace
Abstract: Agent orchestration frameworks — LangGraph, CrewAI, Google ADK, OpenAI Agents SDK, and others — place an external orchestrator above the LLM, tracking state and injecting routing instructions at every turn. We present a controlled comparison showing that for procedural tasks, this architecture is dominated by a simpler alternative: putting the entire procedure in the system prompt and letting the model self-orchestrate. Across three domains — travel booking (14 nodes), Zoom technical support (14 nodes), and insurance claims processing (55 nodes) — we evaluate 200 conversations per condition using LLM-as-judge scoring on five quality criteria. The in-context approach scores 4.53–5.00 on a 5-point scale while a LangGraph orchestrator using the same model scores 4.17–4.84. The orchestrated system fails on 24% of travel, 9% of Zoom, and 17% of insurance conversations, compared to 11.5%, 0.5%, and 5% for the in-context baseline. While external orchestration may have been necessary for earlier models, advances in frontier model capabilities have made it unnecessary for multi-turn conversations following a defined procedure.