Qwen Function Calling Harness Turns 6.75% First-Attempt Success Into 99.8% — Presented at Official Qwen Meetup Korea

r/LocalLLaMA / AutoBE / Qwen Meetup Korea·medium signal

Jeongho Nam presented at the Qwen Meetup Korea on March 26 demonstrating a 'function calling harness' that boosted qwen3-coder-next's initial 6.75% function-calling accuracy to 99.8% across all five Qwen models tested. The system combines lenient JSON parsing (recovering malformed brackets and unquoted keys), automatic type coercion, inline validation feedback with error comments, and self-healing loops that iteratively fix only failed components. The key insight: 'small models are the best QA engineers' for exposing system vulnerabilities during development.