DataFunTalk

Sep 19, 2026 · Artificial Intelligence

LangChain Cuts 65% of Default Agent Harness Tokens: Why Less Context Wins with Stronger Models

LangChain's Deep Agents v0.7 reduces default agent harness base input tokens by 65% by removing default system prompts, shortening tool descriptions 43%, and making TodoListMiddleware opt-in, with evaluations showing no significant accuracy loss across GPT-5.6, Claude Opus 4.8, and GLM 5.2 models.