Add one new skill, and a different skill that used to be picked correctly stops being selected. That is what can happen as an agent's skill library grows 🧩 The usual fixes are retraining the router or collecting labeled routing errors for every skill. This paper shows that you can leave the router and the existing skills alone and rewrite only the incoming skill's name and description, once, at insertion. The authors call the failure routing interference: forgetting that happens at access time, not in model weights. 🔧 Skill++ rewrites the description so it stands apart from similar skills, adds a "does not cover" scope exclusion, and qualifies the name if it clashes. No training and no labels are needed. As the library grows from 27 to 731 skills, the share of queries where all required skills land in the top 5 rises from 36.4% to 76.3% (Claude Haiku 4.5). Errors caused by substitution fall from 46.0% to 6.5%. Skill++: Towards Lifelong Agents via Routing-Aware Skill Refinement Numbers come from the authors' own benchmark, and the study is text-only. #AIAgents# #LLM#