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 sfc-gh-myoung/ai_coding_rules --skill skill-timinggit clone --depth 1 https://github.com/sfc-gh-myoung/ai_coding_rulesWrote 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/sfc-gh-myoung/ai_coding_rules/skill-timing)<a href="https://agentmods.dev/skills/sfc-gh-myoung/ai_coding_rules/skill-timing"><img src="https://agentmods.dev/badge/skills/sfc-gh-myoung/ai_coding_rules/skill-timing.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 | $0.00035 | $0.03916 |
| Opus 5 | $0.00017 | $0.01958 |
| Sonnet 5 | $0.00007 | $0.00783 |
| Haiku 4.5 | $0.00003 | $0.00392 |
Grade A, and why
skill-timing 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 8d 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 — 398 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Timing
Timing instrumentation for skill execution measurement with microsecond precision and anomaly detection.
Quick Start
# Measure a skill execution with checkpoints
Use the skill-timing skill.
skill_name: rule-reviewer
target_file: rules/200-python-core.md
model: claude-sonnet-45
review_mode: FULL
timing_enabled: true
Output: Timing metadata embedded in output file with duration, checkpoints, token costs, and baseline comparison.
Purpose
Enable comprehensive performance measurement and analysis:
- Wall-clock duration - Microsecond precision from start to end
- Checkpoints - Intermediate timing points for bottleneck analysis
- Token tracking - Input/output token counts with cost estimation
- Anomaly detection - Real-time detection of shortcuts and timeouts
- Baseline comparison - Compare against historical averages
- Cross-analysis - Performance across models, agents, and modes
Use this skill when
✅ Use this skill when:
- Measuring skill execution duration
- Comparing performance across models or agents
- Identifying bottlenecks with checkpoints
- Tracking token consumption and costs
- Detecting potential agent shortcuts (suspiciously fast execution)
- Building performance baselines for CI/CD
- Analyzing historical timing trends
❌ Don't use this skill when:
- The skill execution is trivial (<5 seconds expected)
- You're just testing syntax (not measuring actual performance)
- The skill doesn't produce a file output (timing metadata needs a file to embed in)
Inputs
Required (timing-start)
skill_name:string— Name of the skill being timedtarget_file:path— Target file pathmodel:string— Model slug (e.g., claude-sonnet-45)
Required (timing-end)
run_id:hex string (16 chars)— From timing-start outputoutput_file:path— Output file for metadata embeddingskill_name:string— Skill name (for recovery if run_id lost)
Optional (timing-end)
input_tokens:integer(default: none) — Input token countoutput_tokens:integer(default: none) — Output token countformat:string(default:human) — Output format: human, json, markdown, quietdimension_timings:JSON array(default: none) — Per-dimension timing data (see schema below)auto_dimension_timings:flag(default: off) — Derivedimension_timingsautomatically fromdim_<name>_start/dim_<name>_endcheckpoint pairs. Explicitdimension_timingswins if both are supplied (with WARNING).review_mode:string(default:FULL) — Review mode if applicable
What ships with it
15 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.
- CHANGELOG.md 880 B
- examples/baseline-workflow.md 3.9 KB
- examples/basic-timing.md 2.9 KB
- examples/ci-integration.md 6.0 KB
- examples/with-checkpoints.md 4.8 KB
- pyproject.toml 166 B
- schemas/timing-output.schema.json 6.6 KB
- scripts/find_python.sh 1.8 KB runs code
- scripts/skill_timing.py 56 KB runs code
- tests/__init__.py 33 B runs code
- tests/test_per_dimension_timing.py 7.7 KB runs code
- tests/test_skill_timing.sh 21 KB runs code
- workflows/timing-checkpoint.md 1.6 KB
- workflows/timing-end.md 3.8 KB
- workflows/timing-start.md 1.5 KB
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.
- 8d ago First seen · 398 lines · 35 tokens per session scan A e449ef2be670
skill-timing is a skill published in the GitHub repository sfc-gh-myoung/ai_coding_rules (7 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 35 tokens to every session and 3,916 once invoked, about $0.0002 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 2026-08-31.
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