Auditing a Skills Folder as a System: A Synonymous Alias Drives Noncanonical Routes From 0/32 to 15/32

arXiv 2609.13321·high signalXBlueskyLinkedInCopy link

SkillSeam treats a skill collection, not the individual file, as the unit of failure, and maps six design principles to controlled perturbation tests. Flattening the persistence hierarchy raises loaded-skill tokens 60%; a dangling anchor raises total tokens 64% and shifts accuracy -3.1pp; with skill count and context size held fixed, swapping an unrelated control for a synonymous alias raises noncanonical routes from 0/32 to 15/32 and flips half of matched paraphrase pairs; overlapping lanes raise reported ownership conflicts from 0/16 to 14/16; bland triggers drive routing conflicts from 3/32 to 30/32 and inflate loaded-skill tokens 3.7x; and one granularity mis-mix costs -12.5pp accuracy. The byte-differenced variants and a one-screen design checklist are released.