Agent skills are reusable instructions that teach a coding agent how to perform a specific workflow. The best ones are not generic “write better code” prompts. They capture expertise I need occasionally: auditing a Daml contract, mentoring me without writing the answer, removing over-engineering, or running a disciplined development workflow...
Codex already writes a local JSONL transcript for every session. A stop hook can use that transcript to append each prompt and response to Markdown, giving you searchable Obsidian notes without asking the model to summarize anything...