skill-developer

skill-developer is a skill for Claude Code from ratnesh-maurya/cursor-claude-personas. It costs 39 tokens per session (2,876 once invoked), scanned A, a copy of skill-developer, MIT.

A guide for creating and managing Claude Code skills, including their activation rules, configuration files, hooks, and recommended structure. Claude Code is an AI coding assistant that can load these reusable instructions.

In plain words
What is it for?
Use it to create skills, change their triggers, work with hooks, edit skill-rules.json, and debug activation behavior.
Why use it?
It explains how to make skills activate at the right times and follow consistent conventions. It also helps diagnose why a skill is not activating correctly.

Skill for Claude Code

Written for Claude Code: UserPromptSubmit hook event. Also seen: reads .claude/ paths; mentions Claude Code.

Good fit Use it to create skills, change their triggers, work with hooks, edit skill-rules.json, and debug activation behavior.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ratnesh-maurya/cursor-claude-personas/skill-developer
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 ratnesh-maurya/cursor-claude-personas --skill skill-developer
Clone the repo
git clone --depth 1 https://github.com/ratnesh-maurya/cursor-claude-personas

Made for: Claude Code.

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-developer

README.md
[![agentmods](https://agentmods.dev/badge/skills/ratnesh-maurya/cursor-claude-personas/skill-developer/github.svg)](https://agentmods.dev/skills/ratnesh-maurya/cursor-claude-personas/skill-developer)
Your own site
<a href="https://agentmods.dev/skills/ratnesh-maurya/cursor-claude-personas/skill-developer"><img src="https://agentmods.dev/badge/skills/ratnesh-maurya/cursor-claude-personas/skill-developer/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 skill-developer

Your own site · 80×15
<a href="https://agentmods.dev/skills/ratnesh-maurya/cursor-claude-personas/skill-developer"><img src="https://agentmods.dev/badge/skills/ratnesh-maurya/cursor-claude-personas/skill-developer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,876 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 88% copy Near-identical to another mod 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 $0.00039 $0.02876
Opus 5 $0.00019 $0.01438
Sonnet 5 $0.00008 $0.00575
Haiku 4.5 $0.00004 $0.00288

Measured 9d ago against content hash 3aee51807002, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

skill-developer 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 9d 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.

Origin

This is a copy

88% identical to skill-developer — 59 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/skills/skill-developer/SKILL.md · 430 lines

How it starts

The opening of the file, as written. The whole thing — 430 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill Developer Guide

Purpose

Comprehensive guide for creating and managing skills in Claude Code with auto-activation system, following Anthropic's official best practices including the 500-line rule and progressive disclosure pattern.

When to Use This Skill

Automatically activates when you mention:

  • Creating or adding skills
  • Modifying skill triggers or rules
  • Understanding how skill activation works
  • Debugging skill activation issues
  • Working with skill-rules.json
  • Hook system mechanics
  • Claude Code best practices
  • Progressive disclosure
  • YAML frontmatter
  • 500-line rule

System Overview

Two-Hook Architecture

1. UserPromptSubmit Hook (Proactive Suggestions)

  • File: .claude/hooks/skill-activation-prompt.ts
  • Trigger: BEFORE Claude sees user's prompt
  • Purpose: Suggest relevant skills based on keywords + intent patterns
  • Method: Injects formatted reminder as context (stdout → Claude's input)
  • Use Cases: Topic-based skills, implicit work detection

2. Stop Hook - Error Handling Reminder (Gentle Reminders)

  • File: .claude/hooks/error-handling-reminder.ts
  • Trigger: AFTER Claude finishes responding
  • Purpose: Gentle reminder to self-assess error handling in code written
  • Method: Analyzes edited files for risky patterns, displays reminder if needed
  • Use Cases: Error handling awareness without blocking friction

Philosophy Change (2025-10-27): We moved away from blocking PreToolUse for Sentry/error handling. Instead, use gentle post-response reminders that don't block workflow but maintain code quality awareness.

Configuration File

Location: .claude/skills/skill-rules.json

Defines:

  • All skills and their trigger conditions
  • Enforcement levels (block, suggest, warn)
  • File path patterns (glob)
  • Content detection patterns (regex)
  • Skip conditions (session tracking, file markers, env vars)

Skill Types

1. Guardrail Skills

Purpose: Enforce critical best practices that prevent errors

Read the full file on GitHub · 430 lines

Files

What ships with it

6 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. 9d ago First seen · 430 lines · 39 tokens per session scan A 3aee51807002

Subscribe to this mod's changes

skill-developer is a skill published in the GitHub repository ratnesh-maurya/cursor-claude-personas (8 stars, last pushed 5mo ago), licensed MIT. It adds 39 tokens to every session and 2,876 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to skill-developer, differing in 59 lines, and is treated as a copy.

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