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 agentmods add skills/teejayen/arc/principles-checknpx skills add teejayen/arc --skill principles-checkgit clone --depth 1 https://github.com/teejayen/arcWhat 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 | $0.00036 | $0.00903 |
| Opus 5 | $0.00018 | $0.00451 |
| Sonnet 5 | $0.00007 | $0.00181 |
| Haiku 4.5 | $0.00004 | $0.00090 |
Grade A, and why
principles-check 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 2d 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 — 137 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Principles Check
Evaluate any effort, idea, or time allocation against guiding principles.
When to Use
- Before starting: Should I spend time on this?
- After completing: Was this a good use of time?
- Ideating: Which of these ideas best fits the principles?
- Feeling scattered: What should actually get attention?
- Reviewing output: Did this week align with what matters?
The Principles
Source: resources/guiding-principles.md
If no principles file exists, offer to help the user define some. Common principle categories:
Mindset
- Building things that compound vs one-offs
- Skills vs money focus
- Long-term vs reactive thinking
Building
- Protecting time/constraints
- Rhythm vs sprints
- Breadth vs depth at different stages
Foundation
- Health as multiplier
- Presence and relationships
- What enables everything else
Execution
For a Specific Effort/Idea
Read the principles file, then evaluate against each:
## Principles Check: [Effort Name]
| Principle | Score | Reasoning |
|-----------|-------|-----------|
| [Principle 1] | Strong/Moderate/Weak/Neutral | Why |
| [Principle 2] | ... | ... |
| ... | ... | ... |
**Overall Alignment**: Strong / Moderate / Weak / Misaligned
**Verdict**: [Pursue / Defer / Decline / Reconsider approach]
**Key Insight**: [One sentence on what this evaluation reveals]
Scoring:
- Strong: Directly advances this principle
- Moderate: Somewhat aligned, indirect benefit
- Weak: Minimal connection
- Neutral: Not relevant to this principle
- Negative: Works against this principle
For Comparing Options
When deciding between multiple ideas/efforts:
## Principles Check: Comparing Options
| Principle | Option A | Option B | Option C |
|-----------|----------|----------|----------|
| [Principle 1] | Strong | Weak | Moderate |
| [Principle 2] | Moderate | Strong | Weak |
| ... | ... | ... | ... |
**Recommendation**: Option [X] because [reasoning]
**Trade-off acknowledged**: [What you're giving up]
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.
- 2d ago First seen · 137 lines · 36 tokens per session scan A dc226e6a3c37
principles-check is a skill published in the GitHub repository teejayen/arc (5 stars, last pushed 7mo ago), licensed MIT. It adds 36 tokens to every session and 903 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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