Before you install a Claude Code skill, open its SKILL.md and check three things.
These come from a review we ran on the AgentCraft directory in November. We collected every Claude Code skill on GitHub that we had yet to list, 783 in total, and dropped 317 of them. That is about two in five.
The first check alone would have caught 128 of the 317.
Quick guess: did repo stars help predict which skills got dropped?
Barely. Dropped skills came from repos with a median of 1,572 stars. Kept skills came from repos with a median of 1,643. And 220 of the 317 dropped skills live in repos with more than 1,000 stars. Popular repos often ship demos, templates and test fixtures next to their real skills, and those were a large share of what got dropped.
The review prompt drops a skill when it exfiltrates data or secrets, harvests credentials, evades bot detection, anti-fraud or platform rules, is malware or offensive hacking against others, is mainly an ad or paid-API funnel, is a placeholder, template, test fixture or near-empty file, is a personal config useful only to its author, or is sexual content.
| Reason | Skills |
|---|---|
| Placeholder, template, demo or test fixture | 108 |
| Paid API or ad funnel | 65 |
| Only useful to its author or one project | 46 |
| Unsafe | 41 |
| Evades detection or platform rules | 35 |
| Other (thin aliases, failed auto-extraction) | 14 |
| Encrypted, so nobody can read it | 6 |
| Sexual content | 2 |
A few examples:
date command and another fetches the temperature of one fixed city. Great for learning how skills work, useless to install.
We kept 466. One was a duplicate, so 465 went into the directory.
Each skill got one pass from one small model, reading only the first 1,800 characters of its SKILL.md.
We also got an accidental stability test. A name-matching bug sent 266 skills that were already listed through review a second time. Same prompt, same model: 257 kept, 9 dropped. Those 266 are left out of every number above.
A dropped skill also says nothing bad about its repo. Anthropic's own skills repo has a template skill that was dropped here simply because it gives an agent nothing to do.
The full write-up, the exact review prompt and a JSON file with all 317 reasons (names removed) are on the original post:
https://agentcraft.dev/en/blog/claude-code-skills-review-2026-11/ The 465 kept skills are in the AgentCraft skills directory (5,101 skills, with install commands):
https://agentcraft.dev/en/skills/ Disclosure: I'm Adrian Vale and I help run AgentCraft.