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 go-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/go-development)<a href="https://agentmods.dev/skills/jxoesneon/ciel/go-development"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/go-development.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 | $0.00021 | $0.00554 |
| Opus 5 | $0.00010 | $0.00277 |
| Sonnet 5 | $0.00004 | $0.00111 |
| Haiku 4.5 | $0.00002 | $0.00055 |
Grade A, and why
go-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 4d 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: Go Development (Simplicity & Concurrency)
This skill formalizes the development of performant, readable Go services. it prioritizes the "Errors are Values" philosophy and idiomatic concurrency.
Idiomatic Standards
- Zero Value Utility: Design types so their zero value is ready to use (e.g.,
sync.Mutex,bytes.Buffer). - Interface Discipline: "Accept interfaces, return structs." Define interfaces where they are used (consumer-side).
- Error Handling: ALWAYS check errors immediately. Wrap with context:
fmt.Errorf("do X: %w", err). - Returning Early: Handle errors first; keep the "happy path" unindented.
Concurrency Mandates
- Context First: Pass
context.Contextas the first argument to all long-running or I/O-bound functions. - Goroutine Hygiene: Never start a goroutine without knowing how it will stop. Use
errgroupfor coordination. - Channel Safety: Prefer communication by channels over shared memory. Use buffered channels only when necessary for performance.
TDD & Performance (testing)
- Table-Driven Tests: Use anonymous structs for test cases.
- Benchmarks: Mandate
BenchmarkX(b *testing.B)for all performance-critical hot paths. - Fuzzing (1.18+): Use
f.Fuzzfor complex parsers or input validation logic. - Race Detector: ALWAYS run tests with
-racein CI.
Anti-Patterns
- Panic for Control Flow: Using
panicinstead of returning anerror. - Global Mutable State: Initializing DB or Loggers in
init()instead of using dependency injection. - Naked Returns: Using unnamed return variables in functions longer than 10 lines.
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.
- 4d ago First seen · 52 lines · 21 tokens per session scan A 5901bbd353c4
go-development is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed today), licensed Apache-2.0. It adds 21 tokens to every session and 554 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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