State of Agent Skills, Week One: 4% of the Skills We Watch Changed in a Single Night

Skill Harbor lists 2,336 skills from 576 creators. Since October 3, we have kept a fingerprint of every installable file we can reach (2,268 skills, 97% of the catalog) and re-checked them every night. When a file changes, we know before anyone visits the listing. Here is what the first week looked like.

The headline numbers

• 2,268 skills watched nightly, out of 2,336 listed.
• On the night of October 9 to 10: 90 of 2,247 files changed. That is 4.0% of the ecosystem moving in 24 hours.
• Of those 90 changes, 74 were routine (documentation, examples, small fixes) and were re-verified automatically. 16 needed a human look. 6 changed enough that the install prompt itself had to be regenerated. 1 earned a stronger security warning (a payments skill that now moves real funds with real keys).
• 3 listings point to folders that no longer exist upstream. 2 entire creator repositories were deleted since we archived them.

One night, dissected

A change flag means the file's bytes differ from our fingerprint. It does not say whether the change matters. So a person (well, an agent supervised by a person) reads every diff. On October 10, the 16 non-routine changes included a cloud skill that gained a mandatory credentials step, a finance skill whose data source moved, and a slide-deck skill that quietly picked up a new required dependency. Each of those would have made the old install prompt wrong. Each listing now carries the regenerated prompt, with a dated note saying what changed and why.

Changes travel in packs

Skills are rarely edited one at a time. Maintainers push to a shared repository and dozens of listings move at once: on October 10, about 40 of the 90 changes came from a handful of finance repositories updated together. If you use five skills from the same repo, they will tend to change on the same night, and break (or improve) together.

Gone

Three listings (a planning app, a rich-text editor pack, a workspace initializer) link to folders their creators have since removed. The listings stay up with a visible "pending verification" flag, because a dead link is information too. Two repositories in our vendor archive, Telep-IO/muse-platform and PawlanDavid/MuseFi, were deleted outright. Their listings carry the same flag.

The night we cried wolf

Honesty section. On October 9 our checker raised 460 change flags, and 416 of them were our own fault: we had migrated our snapshot addresses from one URL format to another, so every file "changed" against its own baseline. Real upstream changes that night: about 44. We publish this because a change count without a false-alarm rate is marketing, not measurement. Our flags are verified by a human-supervised triage before anything on a listing moves.

Why this matters if you install skills

An install prompt written last month describes last month's files. That is why every Skill Harbor install prompt carries the fingerprint of the reviewed version, why your agent is told to stop and ask you if the file no longer matches, and why listings whose test could not be completed say so on their face. The ecosystem is not a library. It is a river. We watch it so the page you read describes the water as it is today.

What comes next

The watch continues nightly. The next edition will cover a full month, and we will be able to say how many skills changed at least once, how many changed repeatedly, and how long the median skill goes between edits. If a number here ever turns out to be wrong, we will correct it in the open, the same way we handle listings.

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