This post discusses SkillForge, an industrial system from Alibaba Cloud (paper: *SkillForge: Forging Domain-Specific, Self-Evolving Agent Skills in Cloud Technical Support*, ACM SIGIR 2026 Industry Track) that automates both creation and post-deployment evolution of LLM agent skills for cloud technical support.
Key points
- Problem: Existing Skill Creators produce generic templates that lack enterprise domain grounding, and deployed skills stagnate because execution failures are not traced back to skill defects.
- Safe skill format: Skills contain only
SKILL.mdplus predefined, validated tool schemas (tools.json) and knowledge references. Executablescripts/are excluded; all operations run in a virtual file system (VFS), trading functionality for safety, diagnosability, and maintainability. - Domain-Contextualized Skill Creator: A four-stage pipeline (Workflow Mining, Tool Mining, Knowledge Extraction, Skill Synthesis) mines historical expert ticket conversations and internal docs to build the initial skill.
- Three-stage self-evolution loop: 1. Failure Analyzer — parallel four-dimension analysis (Knowledge, Tool, Clarification, Style) with fail/marginal/acceptable aggregation. 2. Skill Diagnostician — batch aggregation of failure cases plus a ReAct agent performing root-cause attribution to specific SKILL.md sections (missing / insufficient / incorrect). 3. Skill Optimizer — targeted edits under Minimal Modification, Do No Harm, and Evidence-Based principles; changes are committed as versioned VFS snapshots.
- Data: 1,883 tickets / 3,737 tasks across five scenarios (Account, Domain, DNS, OSS, ECS), split chronologically into four quarters — three for evolution (v1–v3) and one held-out evaluation set.
- Domain creator vs generic creator: 60.6% vs 56.3% strict consistency (+4.3pp), showing workflow knowledge matters more than tool schemas alone.
- Self-evolution works for all starting points: held-out gains by v3 were +10.99 (expert-written), +9.23 (domain-generated), +11.60 (generic-generated). Even expert-crafted skills improved, meaning automated evolution can surpass manually curated knowledge.
- Beats production: v3 exceeded Alibaba Cloud's long-tuned legacy production system by +13.76pp strict consistency.
- Knowledge Plateau: gains converge; tool/style/clarification failures keep declining, but long-tail knowledge errors hit 0% reduction because reference replies are inconsistent, expert knowledge is tacit, and the design intentionally caps skill bloat. Human-in-the-loop review is framed as a necessary complement, not a replacement.
- Signed URL access to private buckets: missing knowledge that valid signed URLs work directly, missing tool calls, over-clarification — fixed by adding rules, lifecycle knowledge, and tool triggers.
- Mirror back-to-origin configuration: the agent incorrectly asserted that
https://prefixes and/*wildcards were invalid; the knowledge error cascaded into wrong clarification and missed tool calls. - Resource package billing diagnosis: a missing billing-query tool left the agent unable to check purchases, expiry, and remaining quota.
Evaluation results
Case studies (OSS error-diagnosis skill, 108 bad cases)
Industrial takeaways
1. Treat skills as living assets to be cultivated, not one-shot artifacts — build an evolution loop rather than patching manually. 2. Domain grounding is a threshold, not an option; generic frameworks alone will not solve business problems. 3. Know the ceiling: fully automatic text-only optimization cannot eliminate long-tail knowledge errors; combine automation (~80% of frequent issues) with expert review (~20% long-tail). 4. Prefer diagnosability and maintainability over feature completeness — excluding executable scripts makes failure analysis and optimization tractable.
Limitations
The approach fits high-frequency, structured tasks with standardized workflows; it depends on high-quality expert reference replies; the Knowledge Plateau remains unsolved automatically; and evaluation relies on an LLM judge (validated at >90% agreement with five domain experts). Suggested future work includes multimodal inputs, cross-skill coordination, proactive knowledge discovery from good cases, and automating human-in-the-loop review.
Reference: arXiv:2604.08618 — authors from Alibaba Cloud (Xingyan Liu, Xiyue Luo, Linyu Li, Ganghong Huang, Jianfeng Liu, Honglin Qiao). Code and data are not yet open-sourced due to data sensitivity.