SkillCommit: Evolving Agent Skills through Behaviorally Validated Scope Expansion
Organizations: Nanjing University · The Hong Kong University of Science and Technology (Guangzhou)
Abstract
Large language model (LLM) agents can continually improve without parameter updates by converting historical experience into reusable procedural knowledge. However, existing methods often consolidate experience based on semantic similarity or LLM judgments, which may merge superficially related but behaviorally incompatible strategies and thereby degrade performance. To address the issue, we propose SkillCommit, an online skill evolution framework that continuously transforms experience into a hierarchical library of reusable skills. Rather than generalizing from individual experiences immediately, SkillCommit first preserves each experience as an instance-specific patch, retaining its locally validated behavior. As patches accumulate, SkillCommit abstracts those sharing a common behavioral mechanism into higher-level skills. Specifically, for each incoming skill, embedding-based retrieval first identifies candidate related skills. Cross-instance replay and an LLM-based mechanism check determine whether these skills transfer across cases and share a common underlying mechanism. Candidates that pass both checks are abstracted into a higher-level skill and committed only if it preserves the validated behavior of all constituent skills. Experiments on RuleArena, OpenExempt and KOR-Bench demonstrate that SkillCommit consistently improves agent performance across diverse domains. Moreover, the learned skills transfer across model scales and families, enabling cross-model experience transfer.
Figures & tables
| Method | RuleArena | OpenExempt | KOR-Bench | Avg. | |||
|---|---|---|---|---|---|---|---|
| Airline | NBA | EV | EC | Logic | Cipher | ||
| Skill author: DeepSeek-V4-Flash Skill user: DeepSeek-V4-Flash | |||||||
| No Skill | 72.00 | 28.89 | 76.86 | 86.33 | 72.00 | 73.33 | 68.24 |
| ExpeL | 88.00 | 53.33 | 50.17 | 88.36 | 80.00 | 78.67 | 73.09 |
| ReasoningBank | 66.00 | 31.11 | 65.54 | 74.25 | 68.00 | 72.00 | 62.82 |
| ACE | 51.00 | 6.67 | 87.32 | 95.65 | 72.00 | 70.67 | 63.89 |
| Variant | NBA (Acc. ) | EC (Macro-F1 ) |
|---|---|---|
| Full | ||
| No Skill | 28.89_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-59.4%)}}} | 86.33_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-10.1%)}}} |
| Stage removal | ||
| w/o Patch Induction | 53.33_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-25.0%)}}} | 91.41_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-4.8%)}}} |
| w/o Grouping | 42.22_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-40.6%)}}} | 88.87_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-7.4%)}}} |
| w/o Consolidation | 48.89_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-31.3%)}}} | 89.12_{\makebox[31.0pt][l]{{\color[rgb]{0.2,0.2,1}(-7.2%)}}} |
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
| Task | Induct. | Test | Metric |
|---|---|---|---|
| RuleArena Airline | 100 | 100 | strict accuracy |
| RuleArena NBA | 170 | 45 | strict accuracy |
| OpenExempt EC | 210 | 105 | macro-F1 |
| OpenExempt EV | 210 | 105 | macro-F1 |
| KOR-Bench Logic | 175 | 75 | strict accuracy |
| KOR-Bench Cipher | 175 | 75 | strict accuracy |
| Setting | Author user | Purpose |
|---|---|---|
| DS matched | DeepSeek-V4-Flash same | matched model |
| Qwen matched | Qwen3.6-35B-A3B same | matched model |
| Cross-scale | Qwen3.6-35B-A3B Qwen3.5-9B | same family |
| Cross-family | GPT-5.4 Qwen3.5-9B | family + scale |
| Benchmark | Patch author | Solver/replay |
|---|---|---|
| RuleArena | 8,192 | 24,576 |
| OpenExempt | 8,192 | 16,384 |
| KOR-Bench | 16,384 | 8,192 |
| Task family | ||||||
|---|---|---|---|---|---|---|
| RuleArena | 3 | 3 | 4 | forward | 3 | 2 |
| OpenExempt | 3 | 3 | 4 | 2 | 2 | |
| KOR-Bench | 3 | 3 | 4 | 2 | 2 |
| Method | Memory unit | Construction | Test-time use |
|---|---|---|---|
| ExpeL | Insight rules; successful trials | Reflect over successes and failures | Retrieve similar successful trials |
| Reasoning Bank | Structured trajectory memories | Self-judge and append each experience | Retrieve nearest prior experience |
| ACE | Structured global playbook | Generator–Reflector–Curator loop | Load selected frozen playbook |
| Trace2 Skill | Hierarchical skill document | Local patches hierarchical merge | Preload frozen skill file |
| SkillCAT | Core skill and capability nodes | Contrastive edits; assessed updates; hierarchical merge | Route to nodes and prerequisites |
| GSE | Skills and relation graph | Generalize edits; compare candidate and control replays | Route with prerequisites and conflicts |
| Construction outcome | Count |
|---|---|
| Source-validated episode patches | 61 |
| Active higher-level skills | 7 |
| Residual episode patches | 15 |
| Unique episode sources covered by active skills | 46 |
| Root-skill commits | 4 |
| Split-skill commits | 3 |
| Method | Generations | Tokens | When paid |
|---|---|---|---|
| ExpeL | 559 | 5.00M | Offline |
| ReasoningBank | 90 | 0.82M | Online updates |
| ACE | 1,115 | 14.52M | Offline |
| Trace2Skill | 319 | 2.15M | Offline |
| SkillCommit | 952 | 7.72M | Offline |
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