Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/notque/vexjoy-agentnpx agentmods add skills/notque/vexjoy-agent/skill-creatorWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/notque/vexjoy-agent/skill-creator)<a href="https://agentmods.dev/skills/notque/vexjoy-agent/skill-creator"><img src="https://agentmods.dev/badge/skills/notque/vexjoy-agent/skill-creator.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00015 | $0.06789 |
| Opus 5 | $0.00008 | $0.03395 |
| Sonnet 5 | $0.00003 | $0.01358 |
| Haiku 4.5 | $0.00002 | $0.00679 |
Grade A, and why
skill-creator scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 657 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Creator
Create skills and iteratively improve them through measurement.
Output style directive (applies to every generated skill/agent)
Generated SKILL.md and agent bodies must be written as dense informational text focused on accuracy. Minimize prose, maximize signal, no filler.
- No motivational framing, no pep talk, no "this will help you...".
- No repeated restatement of the same constraint in different words.
- Prefer tables, numbered phases, and bullet lists over paragraphs.
- Every sentence must carry information the model will act on; cut anything that is only atmosphere.
- Explanations of "why" stay short and attached to the rule they justify -- one clause, not a paragraph.
New and edited skill files are written to the Dense-Complete Writing standard:
skills/shared-patterns/dense-complete-writing.md. That file is the canonical rule;
the bullets above are its application to skill scaffolding.
This is a generation constraint on the outputs of this skill, not a style note for this skill's own prose. Enforce it during the "Write the SKILL.md" phase and during any agent scaffolding.
The process:
- Decide what the skill should do and how it should work
- Write a draft of the skill
- Create test prompts and run claude-with-the-skill on them
- Evaluate the results -- both with agent reviewers and optionally human review
- Improve the skill based on what the evaluation reveals
- Repeat until the skill demonstrably helps
Figure out where the user is in this process and help them progress. If they say "I want to make a skill for X", help narrow scope, write a draft, write test cases, and run the eval loop. If they already have a draft, go straight to testing.
Creating a skill
Capture intent
Start by understanding what the user wants. The current conversation might already contain a workflow worth capturing ("turn this into a skill"). If so, extract:
- What should this skill enable Claude to do?
- When should this skill trigger? (what user phrases, what contexts)
- What is the expected output?
- Are the outputs objectively verifiable (code, data transforms, structured files) or subjective (writing quality, design aesthetics)? Objectively verifiable outputs benefit from test cases. Subjective outputs are better evaluated by human review.
What ships with it
20 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- agents/analyzer.md 4.8 KB
- agents/comparator.md 4.7 KB
- agents/grader.md 3.9 KB
- assets/eval_viewer.html 57 KB
- references/agent-template.md 18 KB
- references/artifact-schemas.md 8.1 KB
- references/bundled-components.md 2.2 KB
- references/complexity-tiers.md 8.0 KB
- references/domain-research-targets.md 13 KB
- references/enrichment-workflow.md 10 KB
- references/error-catalog.md 9.9 KB
- references/preferred-patterns.md 12 KB
- references/progressive-disclosure.md 8.7 KB
- references/skill-template.md 15 KB
- references/workflow-patterns.md 7.6 KB
- scripts/aggregate_benchmark.py 10.0 KB runs code
- scripts/eval_compare.py 10 KB runs code
- scripts/optimize_description.py 12 KB runs code
- scripts/package_results.py 7.8 KB runs code
- scripts/run_eval.py 6.3 KB runs code
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 3d ago First seen · 657 lines · 15 tokens per session scan A 0eb86256455c
skill-creator is a skill published in the GitHub repository notque/vexjoy-agent (419 stars, last pushed 2d ago), licensed MIT. It adds 15 tokens to every session and 6,789 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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