Rung 02 / The system around the model

Harnesses & Agent Systems

The system around the model — the rung that turns a token price into a task price.

22
Sources
11
Concepts
2
Entities
A machined steel harness buckle with a copper pin, on paper.

In scope: scaffolding and orchestration, tool use, context and memory management, retries and recovery, agent evaluation and benchmarks, failure modes at step three, agent security and the exploitation surface, and cost per completed task. The load-bearing finding this rung already holds: for long-horizon agentic work the harness is often a stronger performance determinant than the model.

A ream of paper with a copper band marking the context boundary, one sheet sliding out below.
OrchestrationTool useAgent memoryFailure modes
Sources compiled for this topic
TypeSourcePublished
ANALYSISPi — a minimal, extensible terminal coding harness
Earendil Inc. and contributors · Earendil Inc.

A configurable, inspectable harness — an INSTRUMENT for testing the binding-constraint thesis, not evidence for it. Publishes no measurement.

PAPERAgentic Reasoning for Large Language Models
Tianxin Wei et al. · Multiple institutions

Three-layer framework for agentic reasoning: foundational, self-evolving, multi-agent

2026-01-18
PAPERFrom LLM Reasoning to Autonomous AI Agents: A Comprehensive Review
Mohamed Amine Ferrag et al. · Multiple institutions

Unified taxonomy of ~60 benchmarks, agent framework comparison, collaboration protocols survey

2026-03-06
PAPERAgentic Tool Use in Large Language Models
Hu Jinchao et al. · Harbin Institute of Technology Shenzhen, TikTok Inc

Unified evolutionary framework for LLM tool use: prompting, supervised, RL paradigms

2026-04-01
PAPERAgentic AI Security & Autonomous Red-Teaming
Ashok Kumar Kanagala · Independent Researcher, Boston, MA

Red-teaming framework for agentic AI: permission escalation, hallucination, orchestration flaws, memory manipulation, supply chain

2026-02-07
PAPERMemory for Autonomous LLM Agents: Mechanisms, Evaluation, and Emerging Frontiers
Pengfei Du · Not specified

Write-manage-read taxonomy, 5 mechanism families, three-dimensional taxonomy for agent memory

2026-03-08
PAPERA-MEM: Agentic Memory for LLM Agents
Wujiang Xu, Zujie Liang, Kai Mei, Hang Gao, Juntao Tan, Yongfeng Zhang · Multiple institutions

Agentic memory with Zettelkasten-inspired note construction, dynamic linking, memory evolution

2025-02-17
PAPERMapping the Exploitation Surface: A 10,000-Trial Taxonomy of What Makes LLM Agents Exploit Vulnerabilities
Charafeddine Mouzouni · OPIT – Open Institute of Technology; Cohorte AI, Paris, France

Large-scale systematic taxonomy of LLM agent exploitation triggers across 12 attack dimensions, identifying goal reframing as the sole reliable trigger while ruling out nine others, with GPT-4.1 achieving complete immunity across 1,850 trials.

2026-04-06
PAPERYour Agent, Their Asset: A Real-World Safety Analysis of OpenClaw
Zijun Wang, Haoqin Tu, Letian Zhang, Hardy Chen, Juncheng Wu, Xiangyan Liu, Zhenlong Yuan, Tianyu Pang, Michael Qizhe Shieh, Fengze Liu, Zeyu Zheng, Huaxiu Yao, Yuyin Zhou, Cihang Xie · UC Santa Cruz, National University of Singapore, Tencent, ByteDance, UC Berkeley, UNC-Chapel Hill

First real-world safety evaluation of a deployed personal AI agent (OpenClaw), introducing the CIK taxonomy and showing that poisoning any single dimension raises attack success rate from 24.6% to 64–74%.

2026-04-06
PAPERThe Amazing Agent Race: Strong Tool Users, Weak Navigators
Zae Myung Kim, Dongseok Lee, Jaehyung Kim, Vipul Raheja, Dongyeop Kang · University of Minnesota Twin Cities, Yonsei University, Google DeepMind

DAG-structured benchmark of 1,400 Wikipedia navigation tasks revealing that current best agents achieve only 37.2% accuracy with navigation errors dominating (27–52% of failures), exposing compositional reasoning as the primary frontier bottleneck.

2026-04-11
PAPERModel-First Reasoning LLM Agents: Reducing Hallucinations through Explicit Problem Modeling
Annu Rana, Gaurav Kumar

Two-phase reasoning: LLMs construct explicit problem models before generating solutions. Reduces constraint violations vs CoT and ReAct across five planning domains.

2025-12-16
PAPERRethinking the Evaluation of Harness Evolution for Agents
Yike Wang, Huaisheng Zhu, Zhengyu Hu, Yige Yuan, Zhengyu Chen, Shakti Senthil, Hannaneh Hajishirzi, Yulia Tsvetkov, Pradeep Dasigi, Teng Xiao · Multiple institutions (inferred UW/AI2 affiliations, not stated verbatim in abstract)

Automatic harness evolution for LLM agents does not consistently outperform simple test-time-scaling baselines under matched feedback/inference budget, and generalizes poorly to held-out tasks (Terminal-Bench 2.1, GPT-5.4 + Claude Opus 4.6) — a methodological check on 'scaffold gains' claims in the agentic-harness literature.

2026-07-14
PAPERStop Comparing LLM Agents Without Disclosing the Harness
Yunbei Zhang, Janet Wang, Yingqiang Ge, Weijie Xu, Jihun Hamm, Chandan K. Reddy · Not stated verbatim on abstract page

Formalizes the Binding Constraint Thesis — for long-horizon agentic tasks across comparable-capability models the execution harness is often a stronger performance determinant than the model — and measures harness-induced variance at 7.80x model-induced variance (18.48 vs 2.37 pp^2, 6/9 ranking reversals) in a 3-model x 3-harness SWE-bench Verified experiment; proposes an ETCSOVG Harness Card disclosure standard + variance-decomposition protocol. Directly on the MenFem 'edge is the harness' thesis.

2026-05-07
PAPERHarness-Bench: Measuring Harness Effects across Models in Realistic Agent Workflows
Yilun Yao, Xinyu Tan, Chao-Hsuan Liu, Yaoming Li, Zhengyang Wang, Wenhan Yu, Zhewen Tan, Yuxuan Tian, Guangxiang Zhao, Lin Sun, Xiangzheng Zhang, Tong Yang · Not stated verbatim on abstract page

Diagnostic benchmark (106 sandboxed offline tasks, 5,194 execution trajectories) that isolates configuration-level harness effects from model capability by fixing task/budget/eval and varying only the harness across model backends; finds substantial variation in completion, quality, efficiency, and failure behavior, and names execution-alignment decoupling as the dominant failure class. Empirical complement to Stop-Comparing.

2026-05-27
PAPERMeasuring Harness-Induced Belief Divergence in Multi-Step LLM Agents
Haiwen Yi, Xinyuan Song · Not stated verbatim on abstract page

Shows the harness changes an agent's multi-step beliefs (progress, risk, recoverability, constraints, failure mode, uncertainty, future success, repair cost, next action) even with task/env/model fixed; introduces a belief-rollout diagnostic, a cross-harness belief-divergence metric split into arrival (interface) + growth (horizon) terms, and BIWM (no-training trajectory alignment). Terminal success often preserved while decision-driving beliefs diverge. Freshest of the July harness cluster.

2026-07-05
PAPERThe Harness Effect: How Orchestration Design Sets the Token Economics of Enterprise Agentic AI
Muayad Sayed Ali et al. (32 authors) · Writer

Controlled orchestration swap, 6 models x 22 locked tasks: cost/task $0.21->$0.12 (-41%), tokens/task 14.2k->8.8k (-38%), completions per Mtok 54.9->92.0, quality at parity (0.78->0.81, directional). Efficiency model-invariant (33-61%); quality gain correlates with baseline model strength r=0.99. VENDOR-RUN (Writer harness + Palmyra X6 are the authors' own).

2026-07-08
PAPERLess Context, Better Agents: Efficient Context Engineering for Long-Horizon Tool-Using LLM Agents
Abhilasha Lodha, Mahsa Pahlavikhah Varnosfaderani, Abir Chakraborty, Abhinav Mithal · Microsoft (Dynamics 365 Finance and Operations)

50-task MCP tool-use benchmark, 5 runs: full history 71.0% completion at 1,480,996 tokens / 14.56h; last-5-tool-calls 79.0% at 535,274 / 5.39h; pruning+summarisation 91.6% (99.64% avg amount) at 553,374 / 5.79h. More context is both 2.68x more expensive AND 20.6 points worse. Cross-model check with Claude Sonnet 4.5.

2026-06-08
REPORTAlphaEvolve: A Gemini-powered coding agent for designing advanced algorithms
Google DeepMind · Google DeepMind

Gemini-powered evolutionary coding agent; 0.7% Google compute recovery; math breakthroughs

2025-05-14
REPORTPrime Agent: A self-improving RLM harness
Prime Intellect · Prime Intellect

Self-improving RLM harness with CRUD-editable harness state (prompts/skills/memory/sub-agents) in a persistent IPython kernel; reports 95.5% ARC-AGI-3 vs a 95.4% human-expert baseline (a 0.1pp margin) and wins on 9 of 11 rows. VENDOR SELF-REPORT with NO matched-budget control -- the exact control that would test agent-harness-evolution's negative result. Loses LongBench v2 to Claude Code 0.746 vs 0.714. Reward hacking observed (bypassed Factorio's rules).

2026-08-05
REPORTverifiers v1: Decomposing Tasksets and Harnesses for Agentic RL & Evaluations
Prime Intellect · Prime Intellect

Decomposes the agent environment into composable taskset / harness / runtime, with an interception server normalising OpenAI Chat Completions, OpenAI Responses and Anthropic Messages while recording traces. Message-DAG traces cut storage from O(n^2) to O(n) in turns, making 100+ turn rollouts practical. Makes the matched-budget harness comparison architectural rather than bespoke. NOTE: actually v0.2.0, a PREVIEW under the verifiers.v1 namespace, released 2026-07-10 — the universal 'v1' framing in secondary coverage overstates maturity. No benchmark in the primary; the 'matched Harbor' and GLM-4.5-Air figures circulating second-hand do not appear in the release note.

2026-07-10
REPORTCan a Language Model Learn Facts Continually in Its Weights?
Charles O'Neill · Baseten

Facts written to weights are question-keyed and do not survive later writes. After 20 sequential writes bare-statement facts retain 1% accuracy vs 46% for broad-study data; 70% of wrong answers contain the MOST RECENTLY written fact; a forgotten fact re-supplied in the prompt recovers to 77-80%. Context, not weights, is the reliable channel — the empirical case for memory being the harness layer job.

2026-07-14
ANALYSISHarness Engineering for Self-Improvement
Lilian Weng · Lil'Log (self-published — page states no affiliation)

Survey of ~39 refs. Lin et al. (2026): harness-UPDATING capability FLAT across Qwen2-32B->Opus 4.6 while harness BENEFIT is NON-MONOTONIC, middle-tier models gaining most. DGM: SWE-bench Verified 20%->50%, Polyglot 14.2%->30.7%. RE-Bench: agents 4x humans at a 2h budget but humans win at 8h and 32h.

2026-07-04
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