# Common Best Practices

Enforce SOLID principles, guard-clause style, function size limits, and...

- Repository: https://github.com/HoangNguyen0403/agent-skills-standard (582 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-best-practices -g -a claude-code -y`
Codex: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-best-practices -g -a codex -y`
Cursor: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-best-practices -g -a cursor -y`
Gemini CLI: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-best-practices -g -a gemini-cli -y`

## Description

Enforce SOLID principles, guard-clause style, function size limits, and intention-revealing naming across all languages. Use when refactoring for readability, applying clean-code patterns, reviewing naming conventions, or reducing function complexity.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Global Best Practices

## **Priority: P0 (CRITICAL)**

## Core Principles

- **SOLID**: Follow SRP (One reason to change), OCP (Open to extension), LSP, ISP, DIP.
- **KISS/DRY/YAGNI**: Favor readability. Abstract repeated logic. No " in case" code.
- **Naming**: Use intention-revealing names (`isUserAuthenticated` > `checkUser`). Match language casing.

## Code Hygiene

- **Size Limits**: Functions < 30 lines. Services < 600 lines. Utils < 400 lines.
- **Early Returns**: Use guard clauses. Avoid deep nesting.
- **Comments**: Explain **why**, not **what**. Refactor bad code; don't comment it.
- **Input**: Validate/sanitize all external inputs.

## Anti-Patterns

- **No Hardcoded Constants**: Use named config/env vars.
- **No Deep Nesting**: Use guard clauses.
- **No Global State**: Prefer dependency injection.
- **No Empty Catches**: Always handle, log, or rethrow.

## References

- [Code Structure Patterns](references/CODE_STRUCTURE.md), file/function organization
- [Effectiveness Guide](references/EFFECTIVENESS.md), practical application examples