REVIEW 3 major objections 5 minor 35 references
Solving tasks sequentially helps LLM agents by 16.9% on average, yet a stored skill library performs no better than pure in-context learning—the gains come from context and feedback, not reusable skills.
Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →
Across five 100-task agent streams, sequential experience improves normalized reward by 16.9% in 14 of 15 model-domain combinations, but explicit skill maintenance matches pure in-context learning (0.602 vs 0.605) and weaker models build larger, less reusable skill pools.
T0 review reviewed 2026-08-05 challenge →
load-bearing objection A reusable 500-task benchmark and a clean three-way comparison, but the headline ICL-vs-skills parity rests on one model, three domains, and single runs, so treat the claim as conditional on the harness. the 3 major comments →
ContinualSkillBench: Can LLM Agents Truly Evolve Their Capabilities?
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
Core claim
On its own terms, the paper claims that current in-context skill evolution mechanisms let agents adapt sequentially but do not yet consolidate experience into robust, transferable skills. The evidence: sequential execution beats independent execution in 14 of 15 model–domain combinations, with an aggregate 16.9% relative gain in normalized reward; but a pure in-context agent that keeps the task order and feedback while dropping the skill library matches explicit skill maintenance (0.605 vs 0.602 normalized reward across Law, Finance, and Healthcare), so most of the sequential gain is contextual adaptation. Explicit skills retain selective value where output or execution formats are rigid—exa
What carries the argument
The load-bearing object is ContinualSkillBench itself: five streams of 100 interconnected subtasks, assembled from a three-tier pool of source benchmarks and ordered by LLM-judged pairwise skill-transfer dependencies under a difficulty constraint, then validated structurally—69.5% of tasks reuse at least one core skill from earlier in their stream, and the curated order beats random permutations on local skill coverage. Evaluation runs each task through a three-turn protocol: instruction with the current skill index, execution, and feedback-driven reflection in which the agent may create or edit skills through create-skill and modify-skill meta-skills. The critical control is the pure in-con
Load-bearing premise
The benchmark's skill-maintenance harness—the three-turn protocol, the create-skill/modify-skill meta-skills, and a prompt that pushes agents to write maximally reusable, task-agnostic skills—is treated as the representative way to do explicit skill maintenance; if a stronger retriever or a prompt that allowed task-specific procedures changed the balance against pure in-context learning, the central conclusion about skill evolution would not generalize beyond this harness.
What would settle it
Run the same five 100-task streams under two modified maintenance regimes—(a) automatic semantic retrieval over the skill library instead of the agent browsing its repository in the prompt, and (b) a maintenance prompt that permits task-specific procedures and notes which task produced each skill—and compare against the same-sequence, no-skill in-context baseline. If either regime makes skill maintenance beat in-context learning by a wide margin across all five domains, the paper's parity finding and its conclusion that agents fail to consolidate experience would be specific to the original ha
If this is right
- Sequential experience helps: running tasks in the engineered order raises normalized reward in 14 of 15 model–domain combinations, a 16.9% relative aggregate gain over independent execution.
- Skill libraries are not the driver: on Law, Finance, and Healthcare, an agent that may create and edit skills scores 0.602 normalized reward versus 0.605 for an agent that simply keeps the conversation and feedback.
- Stored skills still earn their keep where correctness is rigid: explicit skill maintenance beats in-context learning on exact-match and programmatic tasks, doubling Healthcare programmatic reward from 0.250 to 0.500.
- A retrieval-augmented memory baseline behaves like in-context learning—boosting rubric scores without improving exact-match—which the paper reads as further evidence that open-ended gains come from adapting to prior feedback, not from skill abstraction.
- Consolidation quality tracks model capability: the stronger model keeps 205 skills with average quality 7.94; the weaker keeps 384 skills at 5.68 and reuses them less, so fragmentation grows as capability falls.
Where Pith is reading between the lines
- Editorial extension: the parity result is measured under one maintenance regime—a prompt that pushes agents toward maximally reusable, task-agnostic skills and a repository the agent browses before each task. A semantically indexed automatic retriever, or a prompt that permits task-specific procedures, could plausibly move the in-context-versus-skill balance; the paper's conclusion about the limit
- Editorial extension: the benchmark measures reuse within the 100-task stream, not transfer to genuinely new tasks. A held-out probe—tasks of the same core-skill types that never appear in the sequence—would test whether evolved skills transfer at all, which is the load-bearing sense of 'skill'.
- Editorial extension: the skill-quality and reuse statistics suggest a testable hypothesis the paper does not run: per-skill quality scores should predict both downstream call frequency and per-task gains; if quality does not predict reuse, fragmentation may be a symptom of weak retrieval rather than weak consolidation.
- Editorial extension: a natural next experiment is to intervene on consolidation directly—deduplicating, merging, or provenance-tagging skills after each reflection turn—and ask whether those interventions raise exact-match and programmatic rewards beyond the in-context baseline.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper introduces ContinualSkillBench, a benchmark for evaluating whether LLM agents can evolve their capabilities through in-context continual skill learning. It constructs five domain-specific streams of 100 tasks each, ordered by difficulty and cross-task skill dependencies, and evaluates three models (GPT-4o, GPT-5.3-Codex, Claude 4.7 Opus) under independent, sequential, pure in-context learning (ICL), and retrieval-augmented conditions. The headline findings are that sequential execution improves normalized reward in 14 of 15 model-domain combinations, that explicit skill maintenance performs comparably to pure ICL (0.602 vs. 0.605 normalized reward over three domains), and that the weaker model (GPT-4o) accumulates larger, more fragmented skill libraries than GPT-5.3-Codex. The paper concludes that current in-context skill evolution mechanisms support adaptation but struggle to consolidate experience into robust, transferable skills.
Significance. If the results hold, ContinualSkillBench is a valuable evaluation resource: it provides a reproducible, human-reviewed task-ordering methodology, structural validation of skill continuity via permutation tests, and a clear operational separation between raw and normalized rewards. I verified the headline arithmetic in Table 1 and Table 2; the reported counts (14/15, 13/15, 16.9%, 16.2%, and the 0.605 vs. 0.602 parity) are internally consistent. The central empirical claim—that much of the sequential improvement comes from retained context and feedback rather than reusable skill abstraction—is important and falsifiable. However, that claim rests on a specific skill-maintenance protocol, a single model, a single run per condition, and an underspecified normalized-reward definition for the ICL comparison, so the evidence is more conditional than the abstract suggests.
major comments (3)
- [§3.4, Table 2] The normalized reward is defined only for the Ind/Seq intersection ('tasks where both the Sequential and Independent settings successfully generate valid output files'). The ICL rows in Table 2 and the aggregate 0.605 vs. 0.602 comparison use this metric, but the exact task subset for ICL is unspecified. If ICL normalized reward is computed over a different valid-output set (e.g., tasks where ICL produced valid files, or the ICL/Seq intersection), the parity result is not a like-for-like comparison. Please state the common task subset used for all three rows, or recompute all normalized rewards on one fixed intersection, and show per-domain counts.
- [§4.3, Table 2] The headline 'in-context learning performs comparably to explicit skill maintenance' rests on a single run of a single model (GPT-5.3-Codex) over three domains; the aggregate normalized gap is 0.003. No seed/run variance, confidence intervals, or per-task distributions are reported. At this resolution the claim of parity is not quantitatively established. At a minimum, report multiple runs or reframe as 'in one run we observed no consistent aggregate advantage'; ideally add a second model to the ablation, since the abstract generalizes beyond GPT-5.3-Codex.
- [§3.5, Appendix D, Fig. 5] The skill-maintenance protocol is a specific, reusability-biased implementation: the prompt tells the agent to 'Maximize Reusability' and 'Avoid task IDs, temporary names, or absolute paths', and Turn 1 exposes skills as a flat listing with no retrieval or scoring. Appendix H shows that even under this prompt, the most useful-looking generated skills (e.g., 'tatqa-metric-alignment', the Claude medical-advice skill) contain benchmark-specific names and absolute paths, suggesting the protocol both suppresses and imperfectly enforces the intended abstraction. The central conclusion that explicit skill maintenance adds little may be an artifact of this harness; a retriever or a prompt allowing task-specific procedures could change the parity. Please report an ablation with a less constrained maintenance prompt and/or semantic retrieval, or limit the conclusion to 'under this harness'.
minor comments (5)
- [Fig. 3] The axis labels contain garbled glyphs: '/glyph1197umber of Self-Generated Skill Calls per Domain' and 'Total /glyph1197umber of Skills' should be 'Number'.
- [Appendix D, Turn 3 prompt] Typo: 'Y AML front matter' should be 'YAML front matter'.
- [§3.4] Please state explicitly whether raw reward counts tasks with no valid output as zero or excludes them, and specify the denominator for normalized reward when applied to ICL. The current definition only covers Ind vs. Seq.
- [§4.4, Appendix G] The claim that 'less capable models tend to accumulate larger, more fragmented collections' is based on two models (GPT-4o and GPT-5.3-Codex). This is a two-point comparison; please phrase it as an observation about these two models, not a general tendency.
- [References] The NuminaMath reference is formatted inconsistently as 'Jia LI'; other references use title case. Please normalize capitalization.
Circularity Check
No significant circularity: the paper's central claims are empirical, external-reward measurements; no fitted parameter or self-citation chain forces the conclusions.
full rationale
The paper's central claims are grounded in direct experimental comparisons against external evaluators, not in any derivation that reduces to its own inputs. The main Sequential-vs-Independent results (Table 1) use task rewards from exact match, F1, numeric, programmatic, and rubric judges on 100 tasks per domain; the ICL-vs-skills ablation (Section 4.3, Table 2) cleanly separates retained-context/feedback effects from explicit skill maintenance by disabling skill creation in the ICL arm, and the resulting parity (0.605 vs 0.602) is an observed outcome, not a fitted one. The benchmark-construction order is generated from GPT-5.4 pairwise transfer judgments and later checked for skill recurrence using Qwen3-32B annotations and a cosine threshold (Section 3.3, Eq. 1); this is a sanity check of a designed benchmark property, not a prediction derived from a theory, and the paper's conclusions do not depend on this self-validation. There are self-citations (e.g., OneMillionBench cites co-author Jiaqi Li, and the Harbor infrastructure citations may involve overlapping authors), but these are used as external data sources or infrastructure and are not load-bearing for the paper's central claims. The main caveat—that the ICL-vs-skill parity is measured under one specific maintenance prompt and flat-list retrieval—is a generalization/correctness risk, not circularity, because no parameter was fit to the target outcome and the comparison remains fair between the two conditions as implemented. The limitations section is transparent about model and harness coverage, and no uniqueness theorem or ansatz is imported from self-authored prior work to force the choices made.
Axiom & Free-Parameter Ledger
free parameters (1)
- cosine similarity threshold tau =
0.85
axioms (5)
- domain assumption LLM pairwise transfer judgments (GPT-5.4) identify genuine transferable-skill relationships between tasks
- domain assumption Cosine similarity >= 0.85 between mpnet-encoded skill descriptions captures semantic skill equivalence
- domain assumption The predefined curriculum levels reflect true task difficulty
- domain assumption Official source-benchmark evaluators and LLM rubric judges provide valid, cross-condition-comparable scores
- domain assumption The Harbor three-turn protocol with create-skill and modify-skill meta-skills is a representative implementation of explicit skill maintenance
invented entities (1)
-
create-skill and modify-skill meta-skills
no independent evidence
Cite this review
Pith. "Pith review of ContinualSkillBench: Can LLM Agents Truly Evolve Their Capabilities?." pith.science (2026). https://pith.science/paper/IGVUSGZS
@misc{pith2026260803874,
author = {Pith},
title = {Pith review of: ContinualSkillBench: Can LLM Agents Truly Evolve Their Capabilities?},
year = {2026},
howpublished = {\url{https://pith.science/paper/IGVUSGZS}},
note = {Machine review of arXiv:2608.03874}
}
read the original abstract
Modern agent frameworks equip large language models with external skill libraries to solve complex tasks. However, it remains unclear whether these systems can effectively evolve their skills and whether the resulting skills improve task-solving capabilities. To bridge this gap, we introduce ContinualSkillBench, a dynamic evaluation framework for in-context continual skill learning. It covers five representative domains, each containing 100 interconnected subtasks ordered by increasing difficulty and opportunities for cross-task skill reuse. Our experiments show that sequential execution generally improves performance, but the gains vary substantially across models and domains. Moreover, in-context learning performs comparably to explicit skill maintenance on average, suggesting that much of the improvement arises from adaptation to prior context and feedback rather than reusable skill abstraction alone. Explicit skills nevertheless provide selective benefits for tasks requiring reusable procedures or precise outputs. We further find that less capable models tend to accumulate larger, more fragmented collections of task-specific skills. These findings show that current in-context skill evolution mechanisms can support continual adaptation, but still struggle to consistently consolidate experience into robust and transferable skills.
Figures
Reference graph
Works this paper leans on
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[1]
Prerequisite sub-skills: Does Task A require sub-skills (e.g., reading tables, ratio calculation, parsing text) that also appear in Task B? Or vice versa?
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[2]
arXiv preprint arXiv:2602.03587
Cl-bench: A benchmark for context learning. arXiv preprint arXiv:2602.03587. edev2000. 2025. amc12-full dataset. Hugging Face. Accessed: 2026-05-26. Emergent Mind. 2026. Aime 2024 mathematical reason- ing benchmark. Emergent Mind Topics. Accessed: 2026-05-26. Yu Fan, Jingwei Ni, Jakob Merane, Yang Tian, Yoan Hermstrüwer, Yinya Huang, Mubashara Akhtar, Eti...
arXiv 2025
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[3]
Transfer direction: Is the transfer primarily A->B (doing A first helps B), B->A (doing B first helps A), or bidirectional? Required output Respond in this exact JSON format: { "a_helps_b": "YES" | "PARTIAL" | "NO", "b_helps_a": "YES" | "PARTIAL" | "NO", "shared_skills": ["skill1", "skill2"], "reason": "one sentence explaining the main skill relationship"...
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[4]
Avoid task IDs, temporary names, or absolute paths
Maximize Reusability: Keep skills modular and broadly applicable. Avoid task IDs, temporary names, or absolute paths. Figure 5: Prompt used during the reflection and skill- maintenance turn. The agent is instructed to create or revise valid skills through theCreate SkillandModify Skillmeta-skills. Codex Sequential Agent Prompt: Run Ori- entation Turn 0: S...
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[5]
Sharath Chandra Raparthy, Eric Hambro, Robert Kirk, Mikael Henaff, and Roberta Raileanu
Officeqa pro: An enterprise benchmark for end-to-end grounded reasoning.Preprint, arXiv:2603.08655. Sharath Chandra Raparthy, Eric Hambro, Robert Kirk, Mikael Henaff, and Roberta Raileanu. 2023. General- ization to new sequential decision making tasks with in-context learning.Preprint, arXiv:2312.03801. Timo Schick, Jane Dwivedi-Yu, Roberto Dessì, Roberta...
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Jie Zhang, Cezara Petrui, Kristina Nikoli ´c, and Flo- rian Tramèr
Claw-eval: Towards trustworthy evaluation of autonomous agents.Preprint, arXiv:2604.06132. Jie Zhang, Cezara Petrui, Kristina Nikoli ´c, and Flo- rian Tramèr. 2025. Realmath: A continuous bench- mark for evaluating language models on research- level mathematics.Preprint, arXiv:2505.12575. Yuxuan Zhang, Yubo Wang, Yipeng Zhu, Penghui Du, Junwen Miao, Xuan ...
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Shanshan Zhong, Yi Lu, Jingjie Ning, Yibing Wan, Li- han Feng, Yuyi Ao, Leonardo F
Clawbench: Can ai agents complete everyday online tasks?Preprint, arXiv:2604.08523. Shanshan Zhong, Yi Lu, Jingjie Ning, Yibing Wan, Li- han Feng, Yuyi Ao, Leonardo F. R. Ribeiro, Markus Dreyer, Sean Ammirati, and Chenyan Xiong. 2026. Skilllearnbench: Benchmarking continual learning methods for agent skill generation on real-world tasks.Preprint, arXiv:26...
Pith/arXiv arXiv 2026
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[8]
for paragraph-level question answering and information retrieval over complex documents, combined withWritingBench(Wu et al., 2025) to evaluate professional content generation, stylistic refinement, and formatting capabilities. B Pairwise Dependency Evaluation and Graph-based Ordering B.1 Pairwise Dependency Evaluation For each domain, we sample 200 unord...
work page 2025
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[10]
Shared skill practice: Do both tasks exercise the same underlying skill, meaning doing either one gives useful practice for the other?
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[12]
Task Introduction.The agent receives the subtask instruction together with its current 15 Local core-skill coverage gain over random order (cosine >= 0.85) Previous 1 task Previous 5 tasks Previous 10 tasks Law +3.1 pp* q = 0.028 +3.9 pp* q = 0.021 +3.9 pp* q = 0.021 Finance +5.6 pp** q = 0.006 +5.1 pp** q = 0.003 +3.9 pp* q = 0.015 Healthcare +1.9 pp* q ...
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[13]
Its actions and out- puts are recorded for evaluation
Task Execution.The agent performs the task using the available skills, tools, and external resources when necessary. Its actions and out- puts are recorded for evaluation
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[14]
Reflection and Skill Update.After execu- tion, the agent receives evaluator feedback, such as programmatic test results or rubric- level scores. It is prompted to diagnose fail- ures and determine whether the experience should be consolidated into a reusable skill. The agent may create a new skill or revise an existing one using theCreate SkillandMod- ify...
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[15]
Read SKILL.md of create-skill or modify-skill and follow every workflow step
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[16]
Every SKILL.md must begin with YAML front matter: --- name: <skill-name> description: <one-line> --- Otherwise it will not load
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[17]
Abstract feedback into methods, architectural patterns, or universal domain rules
Extract Core Skills: Do not memorize this task. Abstract feedback into methods, architectural patterns, or universal domain rules
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[19]
Read the SKILL.md of create-skill or modify-skill in $HOME/.agents/skills/, and follow its workflow exactly
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[20]
Skills without the header will not be loaded by the framework
EverySKILL.md you write or modify must begin with Y AML front matter. Skills without the header will not be loaded by the framework
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[21]
Abstract feedback into a reusable methodology, architec- tural pattern, or universal domain rule
Extract core skills: do not memorize the solution or hardcode fixes for this specific task. Abstract feedback into a reusable methodology, architec- tural pattern, or universal domain rule
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[22]
Avoid hardcoding task IDs, temporary vari- able names, or absolute file paths
Maximize reusability: keep the documented skill modular and broadly applicable to future unseen tasks. Avoid hardcoding task IDs, temporary vari- able names, or absolute file paths. E Example Task Format and Skill-Dependency Chain To make the benchmark format more concrete, we show an example chain from theFinancedomain. We omit irrelevant tables, filings...
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[23]
Read the provided financial data files
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[24]
Calculate the required financial components
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[25]
Compute the weights for equity and debt in the capital structure
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[26]
Calculate the final W ACC using the given formula
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[27]
This chain illustrates how reusable skills can transfer across subtasks
Handle edge cases. This chain illustrates how reusable skills can transfer across subtasks. Early tasks such as Task 1 and Task 7 require locating values in financial tables and matching rows, columns, periods, and units. Later tasks reuse these operations as subrou- tines for more complex reasoning: Task 35 adds percentage-growth calculation, Task 50 add...
work page 2020
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[28]
- Requested periods and order (for example:`2018 and 2019 respectively`means output`2018 | 2019`)
Parse the question target exactly: - Metric noun phrase (for example:`cash and cash equivalents`,`total liquidity`,`current assets`). - Requested periods and order (for example:`2018 and 2019 respectively`means output`2018 | 2019`). - Required granularity (`exact table amount`vs` approximately`phrasing)
work page 2018
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[29]
Build candidate values from both sources: - Table row values (line items). - Table subtotal/total rows. - Narrative context values (especially management summary sentences)
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[30]
Resolve source selection with this priority: - If the question asks for a line item and only the table has that line item, use the line item. - If the question wording is broad (`had`,`liquidity`, `available`) and context explicitly states a combined figure, prefer the context-stated combined amount. - If context restates table values at different precisi...
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[31]
- Composition check: line item vs subtotal vs combined categories
Validate before finalizing: - Unit check: thousands vs millions. - Composition check: line item vs subtotal vs combined categories. - Time-order check: ensure output order matches` respectively`order. ## Common Pitfalls - Returning a component (`cash & cash equivalents`) when the prompt/judge expects a combined liquidity figure (`cash + short-term investm...
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[32]
Identify task number; determine output path
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[33]
Translate the prompt mentally if non-English
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[34]
Draft a structured answer with: -`key_findings`: bullet list of medically relevant facts -`country_specific`(when relevant): differences across major countries (US/CDC, France/HAS, UK/NHS, Germany/STIKO, WHO) -`recommendation`: clear, safe clinical guidance -`citations`: list of authoritative sources (CDC, WHO , HAS, NHS, NICE, UpToDate, peer-reviewed) -`...
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[35]
WRITE THE FILE. ## Common Topics & Quick References ### Pertussis Booster (whooping cough / coqueluche) - Adults: One Tdap dose; then Td/Tdap booster every 10 years - Pregnancy: Tdap each pregnancy (27-36 weeks US, 16-32 UK, 20-36 France) - Cocoon strategy: parents, grandparents, caregivers of infants <12 mo - Healthcare workers: one dose if not received ...
work page 2024
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Overcoming catastrophic forgetting in neural networks.Proceedings of the National Academy of Sciences, 114(13):3521–3526. Haohang Li, Yupeng Cao, Yangyang Yu, Shashid- har Reddy Javaji, Zhiyang Deng, Yueru He, Yuechen Jiang, Zining Zhu, Koduvayur Subbalakshmi, Guojun Xiong, Jimin Huang, Lingfei Qian, Xueqing Peng, Qianqian Xie, and Jordan W. Suchow. 2024....
Pith/arXiv arXiv 2024
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[2023]
Gaia: a benchmark for general ai assistants. Preprint, arXiv:2311.12983. OpenAI, :, Aaron Hurst, Adam Lerer, Adam P. Goucher, Adam Perelman, Aditya Ramesh, Aidan Clark, AJ Ostrow, Akila Welihinda, Alan Hayes, Alec Radford, Aleksander M ˛ adry, Alex Baker-Whitcomb, Alex Beutel, Alex Borzunov, Alex Carney, Alex Chow, Alex Kirillov, and 401 others. 2024. Gpt...
Pith/arXiv arXiv 2024
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[2026]
Skillcraft: Can llm agents learn to use tools skillfully?arXiv preprint arXiv:2603.00718. Shihan Dou, Ming Zhang, Zhangyue Yin, Chenhao Huang, Yujiong Shen, Junzhe Wang, Jiayi Chen, Yuchen Ni, Junjie Ye, Cheng Zhang, and 1 others
This paper was first reviewed by deepseek-v4-flash on August 5, 2026.
discussion (0)
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