Claude Code Skill Library
2026
A personal library of Claude Code skills — lecture-teacher, cover-letter, mock-exam, notion-notes, obsidian-notes — that collapse workflows I repeat every week into a single command. Building it forced me to get precise about prompt design, tool boundaries, and where an agent should defer to the user.
- Claude Code
- LLM tooling
- Agents
- Markdown
- Five skills covering study, writing and note-taking workflows.
- Each one specifies its own tool permissions and the points where it stops and asks.
The idea
A handful of tasks came back every single week: turn a lecture into something I could be taught from, draft a cover letter against a specific job ad, generate a mock exam, get notes into Notion and Obsidian in a consistent shape. Each one is a prompt I kept rewriting slightly worse than the last time.
A skill is that prompt made permanent — instructions, the tools it is allowed to touch, and the format of what comes back — invoked as one command.
The skills
- lecture-teacher — takes lecture material and teaches it back, working through the parts I ask about rather than summarising the whole deck.
- cover-letter — drafts against a specific posting, using my own material as the source rather than inventing experience.
- mock-exam — generates practice questions in exam format from course material.
- notion-notes — writes notes into Notion in a fixed structure so pages stay comparable.
- obsidian-notes — same idea for a local Obsidian vault, with the linking conventions that vault uses.
What building them taught me
Writing a skill is mostly deciding what it is not allowed to do. A skill with unbounded tool access will happily take an ambiguous instruction and act on the wrong reading of it, so the useful design work is naming the moments where it should stop and ask instead of guess.
The second thing is output format. Once a skill's output has a fixed shape, the work it produces composes with everything else — notes from one skill feed the exam generator, and neither has to know about the other.