Natural-Language Agent Harnesses

Agent performance increasingly depends on harness engineering, but harness behavior is typically embedded in controller code and runtime-specific conventions, making it hard to transfer, compare, or analyze systematically. This work introduces Natural-Language Agent Harnesses (NLAHs), which express harness behavior in editable natural language, and an Intelligent Harness Runtime (IHR) that executes these harnesses through explicit contracts, durable artifacts, and lightweight adapters. The approach enables a code-to-text harness migration path where teams can convert existing harness code into natural-language specifications that are interpretable, version-controlled, and executable by an LLM at runtime.