Skill Drift as Contract Violation: Precision Maintenance for LLM Agent Libraries
A recent study published on arXiv (2605.10990) presents SkillGuardian (\sgname{}), a solution aimed at tackling skill drift within LLM agent skill libraries. Skill drift refers to the gradual deterioration of external services, packages, APIs, or configurations that skills rely on. Current monitoring tools fail to capture changes accurately, focusing on values instead of their functional significance in a skill. For instance, a version string in a comment is irrelevant, whereas the same string in a pinned dependency is crucial. The authors treat skill drift as a breach of contract and suggest deriving executable environment contracts from skill documentation, validating only critical assumptions against established or active conditions. This method transforms ineffective monitoring into a precise maintenance signal. While contract-free CI probes yield a 40% false positive rate, SkillGuardian reports zero false alarms across 599 no-drift and hard-negative scenarios (Wilson 95% CI [0,0.6]%). In scenarios with known drift, SkillGuardian boasts 100% precision. This paper, categorized as a cross announcement, was released on May 26, 2025.
Key facts
- arXiv paper 2605.10990 introduces SkillGuardian for LLM agent skill libraries.
- Skill drift is defined as contract violation for external dependencies.
- Existing monitors produce 40% false positives in contract-free CI probes.
- SkillGuardian raises zero false alarms over 599 no-drift and hard-negative cases.
- SkillGuardian achieves 100% precision in known-drift verification.
- The method extracts executable environment contracts from skill documents.
- Published as a cross announcement on arXiv.
- Wilson 95% CI for false alarms is [0,0.6]%.
Entities
Institutions
- arXiv