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Public story · 2026-08-05 · high
AntiSkillBench tested four defenses against the leak and every one broke once the researchers swapped the underlying model.
Why now: AntiSkillBench landed in the August 5 briefing as the paper to read before you ship a portable persona.
AntiSkillBench found that persona skills leak private details across unrelated conversations in all three frontier agents tested, per the paper posted to arXiv. That's a risk for anyone building products that compress a user into a reusable artifact. The leakage went beyond explicit attributes into communication style and personality traits, drawn from 7,500 dialogue traces built off 50 profiles.
The researchers tested four defenses meant to stop the leak. All four were distillation-dependent, and none held up once the underlying model changed. The paper doesn't say how the compression step decides what to keep, which is the exact point where the leakage starts.
Persona portability and privacy protection are pulling in opposite directions. A file compact enough to carry someone's history between agents is compact enough to carry the parts you didn't mean to hand over. Nothing tested here stops that once you swap in a different model. Watch for a defense that survives a model swap. None does yet, on this evidence.
Each link below shares sources, entities, or timing with this story.
Shared entity: Persona / Same source domain / Shared topic / Earlier coverage / Tension
Both cover Persona; reported by the same outlet (arxiv.org); overlapping topics (agent, persona).
Persona uses MCP / Same source domain / Shared topic / Tension
Linked by a graph relationship (Persona uses MCP); reported by the same outlet (arxiv.org); overlapping topics (agent, communication).
Persona uses MCP / Same source domain / Shared topic
Linked by a graph relationship (Persona uses MCP); reported by the same outlet (arxiv.org); overlapping topics (agent, artifact).
Linked by a graph relationship (Persona uses MCP); reported by the same outlet (arxiv.org); overlapping topics (agent, communication).
Persona uses MCP / Shared topic / Tension
Linked by a graph relationship (Persona uses MCP); overlapping topics (agent, defens); pushes against this story (but).
Linked by a graph relationship (Persona uses MCP); overlapping topics (agent, extended); pushes against this story (against).
Same source domain / Shared topic / Tension
Reported by the same outlet (arxiv.org); overlapping topics (agent, artifact, executable); pushes against this story (but).
Reported by the same outlet (arxiv.org); overlapping topics (agent, executable); pushes against this story (against).