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 python-developmentgit 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/python-development)<a href="https://agentmods.dev/skills/jxoesneon/ciel/python-development"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/python-development/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/python-development"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/python-development.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 | $0.00017 | $0.00409 |
| Opus 5.5 | $0.00007 | $0.00164 |
| Sonnet 5.5 | $0.00003 | $0.00082 |
| Haiku 4.5 | $0.00002 | $0.00041 |
Grade A, and why
python-development 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: Python Development (Idiomatic & Typed)
This skill formalizes the "Modern Python" layer. it prioritizes readability (Zen of Python), explicit type hints, and EAFP error handling.
Idiomatic Standards
- Zen Compliance: Readability over cleverness. Explicit over implicit.
- Type Hints (3.9+): Annotate all public functions using built-in generics (e.g.,
list[str]). - Error Handling: Follow EAFP (Easier to Ask Forgiveness). Use
try/exceptfor expected errors. - Resource Management: ALWAYS use
withstatements (Context Managers) for I/O.
Modern Patterns
- Data Containers: Use
@dataclassfor mutable state andNamedTuplefor immutable state. - Lazy Eval: Prefer Generator Expressions over large List Comprehensions for memory efficiency.
- Validation: Use Pydantic (v2) for strict runtime data validation and parsing.
Testing (pytest)
- TDD: Write failing tests first. 80% coverage target.
- Fixtures: Use
yieldfixtures for setup/teardown. Avoid manual cleanup logic in tests. - Mocking: Use
@patchfor external I/O. Preferautospec=Trueto catch API misuse.
Anti-Patterns
- Mutable Defaults: Using
def foo(x=[]). UseNoneand initialize inside the function. - Bare Except: Catching all exceptions (
except:) instead of specific classes. - Clever Comprehensions: Writing 3-line list comprehensions that are unreadable.
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 34eece118080
- 1mo ago First seen · 51 lines · 17 tokens per session scan A 9e55fccb2003
python-development is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed yesterday), licensed Apache-2.0. It adds 17 tokens to every session and 409 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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