skill-dev

skill-dev is a skill for Claude Code from marcoguillermaz/Tierward. It costs 0 tokens per session (6,113 once invoked), scanned A, original, MIT.

A code-quality review of an existing project, looking for dependencies between modules, repeated database queries, unused exports, common anti-patterns, and overly large components.

In plain words
What is it for?
It helps review application structure, detect N+1 queries, find unused public code, assess large components, and compare findings with a refactoring backlog.
Why use it?
It identifies maintainability and technical-debt problems without changing the code, and ties findings to evidence in specific files.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: model in frontmatter; mentions CLAUDE.md; positional $N argument.

Part of the tierward plugin — 29 skills, 1 command, 1 hook, 1 MCP server shipped together

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.

agentmods
npx agentmods add skills/marcoguillermaz/tierward/skill-dev
Any agent
npx skills add marcoguillermaz/Tierward --skill skill-dev
Clone the repo
git clone --depth 1 https://github.com/marcoguillermaz/Tierward

Made for: Claude Code.

Or install tierward, the plugin that ships this one along with the rest of its 29 skills, 1 command, 1 hook, 1 MCP server.

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 skill-dev

README.md
[![agentmods](https://agentmods.dev/badge/skills/marcoguillermaz/tierward/skill-dev.svg)](https://agentmods.dev/skills/marcoguillermaz/tierward/skill-dev)
Your own site
<a href="https://agentmods.dev/skills/marcoguillermaz/tierward/skill-dev"><img src="https://agentmods.dev/badge/skills/marcoguillermaz/tierward/skill-dev.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,113 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.06113
Opus 5 $0.00000 $0.03057
Sonnet 5 $0.00000 $0.01223
Haiku 4.5 $0.00000 $0.00611

Measured 5d ago against content hash 8d01f49b711b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

skill-dev 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 5d 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.

packages/cli/templates/tier-l/.claude/skills/skill-dev/SKILL.md · 374 lines

How it starts

The opening of the file, as written. The whole thing — 374 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Configuration (adapt before first run)

Replace these placeholders:

  • [LINT_COMMAND] - project's lint command - e.g. eslint ., ruff check, cargo clippy, go vet ./..., swiftlint lint, rubocop, dotnet format --verify-no-changes. If not configured, the skill skips the lint step and proceeds with static checks only.

You are a senior software engineer and code reviewer brought into an existing production codebase to audit code quality and identify technical debt. You are accountable for long-term maintainability, correctness, and delivery speed.

Operating mode for this skill: Audit only - no code changes. Anchor every finding to concrete file paths and code evidence. Do not inflate severity. Distinguish facts from inferences.

Do not optimize for theoretical purity. Optimize for pragmatic, production-grade engineering decisions.

Non-regression constraint - mandatory evaluation criterion: every proposed fix must preserve the observable behavior and user experience of the affected code within its existing perimeter. A fix that changes an external API contract, a UI flow, an error message, a side effect (DB write, email send, redirect), or any user-visible output is not a technical debt fix - it is a behavioral change and must be flagged as an architectural change requiring a full pipeline block, not a backlog entry. When two equivalent fixes exist, the one with the smaller behavioral footprint wins.

Severity model:

  • Critical: production/data/security risk or correctness failure
  • High: architecture flaw or maintainability issue affecting delivery speed or stability; unhandled error on async data-write path; missing null check on external input entering business logic
  • Medium: meaningful improvement with clear benefit, not urgent; over-large module (300+ lines, 4+ responsibilities); console.log in production code
  • Low: TODO comments; consolidation opportunities; magic enum strings already covered by type definitions

Read the full file on GitHub · 374 lines

Files

What ships with it

2 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.

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. 5d ago First seen · 374 lines · 0 tokens per session scan A 8d01f49b711b

Subscribe to this mod's changes

skill-dev is a skill published in the GitHub repository marcoguillermaz/Tierward (4 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 6,113 tokens. 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.