context-engineering
Agent skills work by anchoring procedure, not by adding knowledge News
A study of more than eight thousand agent runs finds that skill files help mainly by stabilizing the order of operations, with explicit knowledge injection accounting for only a small fraction of cases, and that retrieval accuracy collapses as skill libraries grow.
Agent skill libraries now need a librarian, not a folder News
SkillsVote profiles a million-scale corpus of open-source agent skills and admits new ones only through evidence-gated updates after execution, arguing that indiscriminate additions to a skill library pollute every future run's context.
Two papers attack the same waste: coding agents rediscovering the same repository every session News
CodeNib builds reusable lexical, semantic and structural views of a repository per commit and cuts an agent's exploration tokens by 50 to 87%, while a companion benchmark finally measures the file-finding stage that patch-success scores hide.
The harness: the code around a model that decides how smart it looks Lesson
An agent harness is the ordinary software wrapped around a language model that decides what it sees, what tools it can call, and what it remembers between steps, and changing it can swing benchmark scores several times over without touching the model at all.
Anthropic says it deleted over 80% of Claude Code's system prompt with no measurable loss News
Anthropic reports removing more than 80% of Claude Code's system prompt for its newest models without measurable degradation on internal coding evaluations, moving the deleted guidance into tool schemas, skills and memory instead.
AREX-Skill Tool
A public library of over 5,000 verified agent skills distilled from 1,000 GitHub repositories, organised into 20 areas and 178 capability families. A router narrows a request to an area, family, repository and workflow so only the needed branch loads. Uses the open Agent Skills format for portability.