Your platform team spent two weeks building a release-notes skill and announced it in the engineering channel. Three weeks later, someone asks whether anyone uses it. Nobody knows.
The Problem
Skills and shared agent instructions are how a platform team scales good practice. But once a skill ships, it disappears into individual sessions. You can't tell whether it was adopted, by whom, or whether one heavy skill is quietly adding cost to every session that loads it.
How It Cascades
Good skills go unadopted because nobody can show they work.
Expensive skills keep running because nobody can see what they cost per use.
Platform teams can't show the return on the time they put into agent tooling.
The Insight
A skill is a product with users. Measure it like one: who uses it, how often, and what each use costs.
The Solution
VibeCheck's Skills ledger lists every skill observed in your team's Claude Code, Codex and Cursor sessions. Each row shows invocations, how many people used it, how many sessions it appeared in, and uncached tokens and estimated cost, in total and per invocation. Search for the skill you shipped, pick the weeks since launch or set a custom range, and sort by any column. Each engineer sees their own skill use the same way.
The Outcome
You can show which skills caught on and which didn't, retire or slim down the ones that cost too much per use, and point the platform roadmap at what the team actually runs.