CentaurBench: Benchmarking LLM Capabilities on Augmenting vs. Automating Real-World Work Tasks
Organizations: Data Innovation and AI Lab (DIAL) at the Haas School of Business, UC Berkeley · UC Berkeley · UC Berkeley and NBER
Abstract
Most LLM benchmarks rank models on their ability to automate work tasks. In practice, however, models are often used to assist other (human or LLM) agents. The question that drives model selection is therefore not only which model produces the best output, but which model most improves the work of another (weaker) agent. We introduce a unified framework that evaluates the capability of models to automate and augment another agent's performance. Across seven economically grounded real-world tasks, an assistant model writes assistance text for a standardized lower-capacity worker model, which produces the deliverable. In automation mode, the assistant produces the output directly. Outputs are scored through blind pairwise comparisons by an LLM judge panel with task-specific rubrics, replicated across ten runs. Rankings across the two regimes are only modestly correlated, and the automation winner loses augmentation on five of seven tasks. Assistance is not reliably positive. The unaided worker outranks every assisted condition on three tasks, and only one model's guidance beats no guidance on average. These results suggest that automation ability is an incomplete proxy for assistance quality, motivating benchmarks that evaluate models according to the roles they play in human-AI and multi-agent systems.
Figures & tables
| Task | Source | Task type | Deliverable |
|---|---|---|---|
| Menu Planning | GDPval | Structured planning | Seven-day constrained meal plan |
| Travel Planning | GDPval | Structured planning | Tokyo itinerary under fixed budget |
| Market Trends Analysis | GDPval | Professional / analytical | Client brief on natural gas trends |
| Operations Research Analysis | Anthropic Economic Index | Professional / analytical | Executive logistics optimization memo |
| Tax Preparation | Designed task | Professional / analytical | Tax discrepancy review and correction guidance |
| Counseling | Anthropic Economic Index | Human-facing interactive | Supportive counseling-style response |
| Task | Spearman | -value |
|---|---|---|
| Tax Preparation | 0.85 | 0.004 |
| Menu Planning | 0.64 | 0.066 |
| Tutoring Session Planning | 0.50 | 0.166 |
| Counseling | 0.25 | 0.516 |
| Operations Research Analysis | 0.17 | 0.668 |
| Market Trend Analysis | 0.10 | 0.798 |
| Task, assistant (rank) | Assistance-text excerpt | |
|---|---|---|
| Trait 1: Specificity beyond the prompt (contingency) | ||
| Good | Market trends, GPT-5-Mini (1) | “For each trend, plan 2 to 3 succinct bullets: core observation, primary driver(s), and potential market implication…a short preface about methodology and data vintage.” |
| Bad | Market trends, GPT-4.1 (9) | “Ensure you understand the expectation to discuss how various factors (supply, demand, weather, storage, LNG exports, infrastructure, policy) interact…” (restates the prompt’s factor list) |
| Trait 2: Explicit structure and ordering | ||
| Good | Travel planning, Gemini-3.1-Pro (3) | Enforces assumptions and clarifying questions “ before the provisional itinerary,” with named sections in explicit order: Introduction Budget Breakdown Daily Itinerary Conclusion. |
| Bad | Travel planning, GPT-O4-Mini (9) | “Determine sequence and hierarchy of information for clarity and flow”; instructs worker to “populate each section with neutral placeholders… [Day 1: transportation placeholder] ”; no ordering is prescribed. |
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
| Model | Provider | Automation | Augmentation | Judge |
| GPT-3.5-Turbo | OpenAI | ✓ | Worker | |
| Claude-Opus-4.8 | Anthropic | ✓ | ✓ | ✓ |
| Claude-Sonnet-4.6 | Anthropic | ✓ | ✓ | |
| DeepSeek-V3.1 | DeepSeek | ✓ | ✓ | ✓ |
| Gemini-3.1-Pro | ✓ | ✓ | ✓ | |
| GPT-4.1 | OpenAI | ✓ | ✓ | ✓ |
| Task | Automation | Augmentation |
|---|---|---|
| Counseling | GPT-OSS-120B | GPT-4.1 |
| Market Trends | Claude-Opus-4.8 | GPT-O4-Mini |
| Menu Planning | GPT-5-Mini | GPT-5-Mini |
| Operations Research | Gemini-3.1-Pro / GPT-OSS-120B | GPT-3.5-Turbo (plain) |
| Tax Prep | GPT-5-Mini | GPT-3.5-Turbo (plain) |
| Travel Agent | GPT-5-Mini | GPT-3.5-Turbo (plain) |
LLM Agent Evaluation
Large language model agent evaluation measures whether tool-using systems complete tasks reliably, safely, and efficiently.
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