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 jdrhyne/agent-skills --skill senior-engineeringgit clone --depth 1 https://github.com/jdrhyne/agent-skillsWrote 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/jdrhyne/agent-skills/senior-engineering)<a href="https://agentmods.dev/skills/jdrhyne/agent-skills/senior-engineering"><img src="https://agentmods.dev/badge/skills/jdrhyne/agent-skills/senior-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/jdrhyne/agent-skills/senior-engineering"><img src="https://agentmods.dev/badge/skills/jdrhyne/agent-skills/senior-engineering.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 12 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
- low Excessive Agency · line 13 Skill's behavior or capabilities extend beyond its stated purpose. Scope creep allows an agent to perform actions unrelated to its documented functionality, increasing the attack surface.Fix: Limit the skill's scope to its documented purpose. Remove instructions that enable the agent to perform actions outside its stated functionality.
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 | $0.00052 | $0.01082 |
| Opus 5.5 | $0.00021 | $0.00433 |
| Sonnet 5.5 | $0.00010 | $0.00216 |
| Haiku 4.5 | $0.00005 | $0.00108 |
Grade A, and why
senior-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.
How it starts
The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Senior Engineering Principles
Guidelines for building software with the judgment and discipline of a senior engineer.
Safety Boundaries
- Do not treat these principles as permission to skip user approval for destructive or high-risk changes.
- Do not expand scope beyond the user's request just because a broader rewrite seems cleaner.
- Do not invent validation results; report what was actually checked and what remains unverified.
Before Writing Code
Define Done First
- What does success look like? Write it down.
- What are the acceptance criteria?
- How will you verify it works?
Identify Load-Bearing Decisions
- Which choices are hard to reverse? → More scrutiny
- Which are easily changed? → Decide fast, move on
- Reversible decisions don't need consensus
Decompose Before Building
- Break work into clear, testable units
- Each unit should be independently verifiable
- If you can't explain the pieces, you don't understand the whole
Surface Risks Upfront
- What could go wrong?
- What are the dependencies?
- What's the rollback plan?
- Time-box exploration — analysis paralysis is real
Interface First, Implementation Second
- Define the contract (types, API shape, error cases) before internals
- Forces clarity on what you're actually building
- Implementation becomes "fill in the blanks"
Ask: What's the Simplest Thing That Could Work?
- Start there. Add complexity only when the simple version fails.
- Most features need 20% of what we imagine.
During Build
Always Have a Runnable State
- Never be more than 30 mins from something that compiles/runs
- Commit working checkpoints frequently
- Big-bang integration is where projects die
Prefer Incremental Over Big-Bang
- Ship small, verify, iterate
- Each step should be independently deployable if possible
- Reduce blast radius of mistakes
Instrument As You Build
- Add logging/metrics while coding, not when debugging prod
- "I wish I had visibility into X" = you waited too long
- Observability is a feature, not an afterthought
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 First seen · 148 lines · 52 tokens per session scan A c3146fa979f0
senior-engineering is a skill published in the GitHub repository jdrhyne/agent-skills (240 stars, last pushed 1mo ago), licensed MIT. It adds 52 tokens to every session and 1,082 once invoked, about $0.0002 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 2026-08-30.
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