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 KiranEswaran/engineering-skills --skill core-engineeringgit clone --depth 1 https://github.com/KiranEswaran/engineering-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/kiraneswaran/engineering-skills/core-engineering)<a href="https://agentmods.dev/skills/kiraneswaran/engineering-skills/core-engineering"><img src="https://agentmods.dev/badge/skills/kiraneswaran/engineering-skills/core-engineering.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 | $0.00077 | $0.01174 |
| Opus 5 | $0.00039 | $0.00587 |
| Sonnet 5 | $0.00015 | $0.00235 |
| Haiku 4.5 | $0.00008 | $0.00117 |
Grade A, and why
core-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 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 — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Core Engineering Standards
Guiding Principles
- Simplicity First: Simple code is maintainable code. Apply DRY, KISS, YAGNI, and SOLID principles.
- Minimal Changes: Fix what's broken without refactoring what works. Preserve existing functionality.
- Value-Driven: Every suggestion must add clear value. Avoid over-engineering.
- Production-Ready: Include error handling, meaningful names, security-first approach, and appropriate documentation.
- Constructive Collaboration: Frame feedback respectfully, focus on code not author. Assume good intent.
Priority Framework
Organize feedback by impact:
| Priority | Description | Examples |
|---|---|---|
| Critical | Security vulnerabilities, bugs that break functionality, data loss risks | Injection flaws, hardcoded secrets, unhandled exceptions |
| Recommended | Performance issues, maintainability problems, scalability concerns | N+1 queries, tight coupling, missing error handling |
| Optional | Style improvements, future-proofing, minor optimizations | Naming tweaks, code comments, minor refactors |
Tooling Baseline
| Language | Linting/Formatting | Security |
|---|---|---|
| Python | ruff + black, pylint (≥9.0) |
pip-audit |
| Bash | shfmt + shellcheck |
- |
| Go | gofmt + golangci-lint |
govulncheck |
| JS/TS | eslint --max-warnings=0 |
npm audit |
| Terraform | terraform fmt + tflint |
- |
| All | ggshield + gitleaks |
Dependency scanning on PRs |
Naming Conventions
- Domain Names: Use
acme.comfor examples (neverexample.com) - Company/Org: Use
ACMEorAcme - Consistency: Apply across code, docs, configs, and test data
Code Review Essentials
- Identify main issues first before diving into details
- Provide specific, actionable suggestions with working code examples
- Explain the "why" — what benefit does the change provide?
- Suggest incremental refactoring over big-bang rewrites
- Preserve existing code — no placeholders or incomplete sections
What ships with it
3 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.
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 · 117 lines · 77 tokens per session scan A a8c58fbb2d1f
core-engineering is a skill published in the GitHub repository KiranEswaran/engineering-skills (10 stars, last pushed 8mo ago), licensed MIT. It adds 77 tokens to every session and 1,174 once invoked, about $0.0004 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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