{"id":"nr-agent-reliability-gains-are-coming-from-the-harness-and-learned-experi-89264d","slug":"agent-reliability-gains-are-coming-from-the-harness-and-learned-experi-89264d","type":"raw_signal","title":"Agent reliability gains are coming from the harness and learned experience, not bigger models","description":"A behavioral harness took a cheaper coding model from 3 of 10 successful runs to 10 of 10, at 33% less per run than the larger model.","observed_at":"2026-10-23","record_date":"2026-10-23","date_kind":"observed_at","novelty":"notable","source_platform":"newruntime.com","topics":[],"entities":["Naresh Jain","GPT-6 Luna","GPT-6 Sol","Specmatic","Codex","IBM Research","ALTK-Evolve","τ²-bench","GPT-4.1","GPT-5.5"],"related_patterns":["harness-architecture-outlives-model-choice","verification-bandwidth-is-the-scarce-resource"],"source_url":"https://martinfowler.com/articles/are-harnesses-worth-the-cost.html","source_urls":["https://martinfowler.com/articles/are-harnesses-worth-the-cost.html","https://huggingface.co/blog/ibm-research/altk-evolve-bc","https://kiro.dev/blog/how-kiro-fixes-itself","https://www.cerebras.ai/blog/a-smarter-model-won-t-save-your-bad-harness","https://aistudio.google.com/learn/agentic-video-understanding-with-gemini"],"why_it_matters":"A behavioral harness took a cheaper coding model from 3 of 10 successful runs to 10 of 10, at 33% less per run than the larger model. Learned memory put an older model at the top of a customer-service leaderboard without changing its weights. Amazon's Kiro now mines its own runs to propose prompt and tool fixes. Before paying for a model upgrade, builders should invest in loop design, memory and self-tuning harnesses.","verification_level":"source-linked","signal_type":"synthesis","synthesis_of":[{"slug":"cheap-but-unreliable-smaller-ai-models-are-tempting-057529","title":"Cheap, but unreliable. Smaller AI models are tempting for coding tasks because they cost less, and teams rarely choose a model on raw intelligence alone.","url":"https://newruntime.com/posts/cheap-but-unreliable-smaller-ai-models-are-tempting-057529/"},{"slug":"altk-evolve-how-learned-memory-tops-the-2-fae5de","title":"ALTK-Evolve: How learned memory tops the τ²-bench leaderboard on customer service tasks without a frontier model","url":"https://newruntime.com/posts/altk-evolve-how-learned-memory-tops-the-2-fae5de/"},{"slug":"on-tuesday-amazon-unveiled-kiro-trace-an-internal-a63578","title":"On Tuesday, Amazon unveiled Kiro-trace , an internal tracing system that improves Kiro, Amazon's AI coding agent, from its own runs.","url":"https://newruntime.com/posts/on-tuesday-amazon-unveiled-kiro-trace-an-internal-a63578/"},{"slug":"a-smarter-model-won-t-save-your-bad-36f226","title":"A Smarter Model Won’t Save Your Bad Harness","url":"https://newruntime.com/posts/a-smarter-model-won-t-save-your-bad-36f226/"},{"slug":"google-launched-agentic-video-understanding-for-gemini-flash-ad81da","title":"Google launched agentic video understanding for Gemini Flash models, cutting long-form video costs up to 66%.","url":"https://newruntime.com/posts/google-launched-agentic-video-understanding-for-gemini-flash-ad81da/"}],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"signal:agent-reliability-gains-are-coming-from-the-harness-and-learned-experi-89264d","retrieval_nugget":"A behavioral harness took a cheaper coding model from 3 of 10 successful runs to 10 of 10, at 33% less per run than the larger model.","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/signals/agent-reliability-gains-are-coming-from-the-harness-and-learned-experi-89264d/","markdown":"https://newruntime.com/signals/agent-reliability-gains-are-coming-from-the-harness-and-learned-experi-89264d.md","json":"https://newruntime.com/signals/agent-reliability-gains-are-coming-from-the-harness-and-learned-experi-89264d.json"},"next_reads":[{"type":"collection","path":"/signals/","url":"https://newruntime.com/signals/","title":"Raw Signals","reason":"Open every source-linked raw signal.","media_type":"text/html","json_url":"https://newruntime.com/signals.json"},{"type":"collection","path":"/source-ledger.json","url":"https://newruntime.com/source-ledger.json","title":"Source Ledger","reason":"Inspect the public source evidence graph.","media_type":"application/json"}]}