Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add jxoesneon/Ciel --skill ciel-skill-engineeringgit clone --depth 1 https://github.com/jxoesneon/CielWrote 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/jxoesneon/ciel/ciel-skill-engineering)<a href="https://agentmods.dev/skills/jxoesneon/ciel/ciel-skill-engineering"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/ciel-skill-engineering/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/jxoesneon/ciel/ciel-skill-engineering"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/ciel-skill-engineering.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00024 | $0.00480 |
| Opus 5.5 | $0.00010 | $0.00192 |
| Sonnet 5.5 | $0.00005 | $0.00096 |
| Haiku 4.5 | $0.00002 | $0.00048 |
Grade A, and why
ciel-skill-engineering 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 1mo 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.
What it actually says
CIEL ADAPTATION: Skill Engineering (The Reproduction Layer)
This skill formalizes the creation, packaging, and iteration of CIEL skills. it mandates a TDD-based documentation approach.
The Skill Lifecycle
- Initialize: Use
init_skill.cjsto generate a structured template (scripts/refs/assets). - Edit (TDD):
- RED: Identify a task where an agent fails/hallucinates without procedural guidance.
- GREEN: Write imperative instructions in
SKILL.mdto bridge that gap. - REFACTOR: Move detailed references to
references/to keep the primary skill lean.
- Package: Run
package_skill.cjsto validate YAML and ensure "No Placeholders." - Install: Deploy to
--scope workspace(repo-specific) or--scope user(global).
Design Principles
- Concise Metadata: The description MUST specify "When to use." Summary of "How" is prohibited in frontmatter.
- Progressive Disclosure: Keep
SKILL.md< 500 lines. Use linked.mdfiles for examples and deep schemas. - Degrees of Freedom: Use high-freedom (text) for heuristics; low-freedom (scripts) for fragile sequences.
Resource Bundle Patterns
- Scripts: For deterministic reliability (e.g., PDF rotation). Must output agent-friendly JSON/STDOUT.
- References: For schemas/docs that should be loaded ONLY when needed.
- Assets: Templates/Icons that are copied into the output, not read into context.
Anti-Patterns
- Placeholder Rot: Committing a skill with
// Refine implementation logic to align with Ciel 1.0 standards.or...markers. - Amnesiac Description: Describing the tool's history instead of its triggering context.
- Excessive Freedom: Using text instructions for a complex API sequence that requires a script.
What ships with it
1 file 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.
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.
- 1mo ago Changed · -13 lines 33362bc1e757
- 1mo ago First seen · 54 lines · 24 tokens per session scan A 58d62542b21a
ciel-skill-engineering is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed yesterday), licensed Apache-2.0. It adds 24 tokens to every session and 480 once invoked, about $0.0001 per session on Opus 5.5. 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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