battle-tested-engineer

battle-tested-engineer is a skill for Claude Code from sayeed1999/agent-skills. It costs 74 tokens per session (1,181 once invoked), scanned A, original, MIT.

A coding skill that applies simple engineering judgment to new code, refactors, tests, and frontend work. It favors small changes and very brief explanations while code is being changed.

In plain words
What is it for?
Use it for code reviews, legacy cleanup, test writing, data-backed interface work, and complaints about bloated or overcomplicated code.
Why use it?
It helps an agent avoid over-engineering, unnecessary features, and broad edits that could break working code.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the agent-skills plugin — 1 skill shipped together

Good fit Use it for code reviews, legacy cleanup, test writing, data-backed interface work, and complaints about bloated or overcomplicated code.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sayeed1999/agent-skills/battle-tested-engineer
Install

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.

Any agent
npx skills add sayeed1999/agent-skills --skill battle-tested-engineer
Clone the repo
git clone --depth 1 https://github.com/sayeed1999/agent-skills

Made for: Claude Code.

Or install agent-skills, the plugin that ships this one along with the rest of its 1 skill.

Wrote 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.

agentmods badge for battle-tested-engineer

README.md
[![agentmods](https://agentmods.dev/badge/skills/sayeed1999/agent-skills/battle-tested-engineer/github.svg)](https://agentmods.dev/skills/sayeed1999/agent-skills/battle-tested-engineer)
Your own site
<a href="https://agentmods.dev/skills/sayeed1999/agent-skills/battle-tested-engineer"><img src="https://agentmods.dev/badge/skills/sayeed1999/agent-skills/battle-tested-engineer/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.

agentmods 80×15 button for battle-tested-engineer

Your own site · 80×15
<a href="https://agentmods.dev/skills/sayeed1999/agent-skills/battle-tested-engineer"><img src="https://agentmods.dev/badge/skills/sayeed1999/agent-skills/battle-tested-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 74 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,181 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00074 $0.01181
Opus 5 $0.00037 $0.00590
Sonnet 5 $0.00015 $0.00236
Haiku 4.5 $0.00007 $0.00118

Measured 12d ago against content hash 6d8e926ea25a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

battle-tested-engineer 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 12d 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.

skills/battle-tested-engineer/SKILL.md · 113 lines

How it starts

The opening of the file, as written. The whole thing — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Battle Tested Engineer

Goal: least code, fix problem, no break working stuff.

Output style

  • Explain in simple terms like a human.
  • Write specs as if any engineer would easily catch. Every spec/adr/decision doc/explanation/answer should be simple, easy to understand for human engineers with no over-complication, no unnecessary details, no repeated redundant explanation in multiple blocks.
  • Document core business workflows, decisions, algorithms, approaches.
  • No extra explanation than asked.
  • No decorative tables, emoji, tool narration. Errors: quote shortest relevant line only.

Example:

User: rename foo to bar in utils.py
Bad: I'll rename the function foo to bar in utils.py now. This should be straightforward...
Good: renamed. utils.py:12

1. Think before code

  • State assumption, no guess.
  • Multi interpretation → show all, no pick.
  • Unclear ask → stop, name confusion, ask.
  • Simpler way exist → say it.

2. Simplicity

  • Senior-line estimate; actual >4x → cut.
  • No unrequested feature/flexibility/config/error-handling for impossible case.
  • Prefer stdlib/dep over hand-roll.
  • Function many unrelated thing → split single-responsibility. Already one thing → leave.
  • YAGNI/DRY/SOLID when shape need — not checklist.
  • Comment why, not what.
  • Red flag: single-use abstraction, one-method "manager", options object one caller.

3. Architecture boundaries (Clean Architecture)

  • Business rules are the center. Code depends inward, never outward.
  • Frameworks are tools, not foundations. UI, ORM, web framework, database are replaceable details.
  • Controllers thin: translate input/output only. No business decisions.
  • Use cases focused: one use case = one application action.
  • Domain models clean: no database, HTTP, framework, or infrastructure knowledge inside.
  • Business behavior near business data. Do not scatter rules across controllers/services/helpers.
  • Interfaces at real boundaries: external systems, storage, APIs, queues. No fake abstraction.
  • Dependencies explicit. Avoid hidden globals, magic imports, service locators, or implicit coupling.
  • Composition over inheritance. Assemble behavior instead of deep class trees.
  • Organize around business capabilities, not technical layers.

Read the full file on GitHub · 113 lines

Changes

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.

  1. 12d ago First seen · 113 lines · 74 tokens per session scan A 6d8e926ea25a

Subscribe to this mod's changes

battle-tested-engineer is a skill published in the GitHub repository sayeed1999/agent-skills (6 stars, last pushed 11d ago), licensed MIT. It adds 74 tokens to every session and 1,181 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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