Skill issue: Lessons from skilling up coding agents to use Langfuse - Marc Klingen, Clickhouse
Source
AI Engineer
Author
AI Engineer
Date
Terms in this piece · Glossary
agent skill — A reusable instruction file that teaches an agent how to do one job well — the procedure, the tools, and what counts as done.
pretraining — The first, biggest phase of building a model: training it on enormous amounts of text so it learns language, facts, and reasoning in general.
Why it matters
If you're building skills to make coding agents reliably use your library or docs, this covers concrete patterns—search endpoints over crawling, referencing instead of duplicating, and why optimizing a agent skillA reusable instruction file that teaches an agent how to do one job well — the procedure, the tools, and what counts as done.Full definition →'s 'target function' can silently remove the doc-fetching steps that keep it reliable.
Key quotes
“skills are kind of like a formalized shortcut to make things more reliable where you historically would have built a workflow”
Marc Klingen
“looking at traces still like gets you to like 80% of the detail”
Marc Klingen
“the target function really matters. Like I think it's it sounds obvious, but for us defining like the right target function was very hard”
Marc Klingen
“I think it's not a surprise that I think nobody reads documentation themselves”
Marc Klingen
“Question is do you even need to ask? Like I think you only need to ask if the skill is kind of like more trusted than the public web. If it's like same trust level, then why even bother asking?”
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