skill-developer

To create a Claude Code skill, define a SKILL.md file with YAML frontmatter, specify trigger patterns, and register it in skill-rules.json to ensure progressive disclosure and maintainable skill ecosystems.

UserPromptSubmit and PreToolUse hooks are mechanisms enabling proactive skill activation and gentle reminders, allowing Claude Code skills to trigger automatically based on user intent and tool usage context.

The 500-line rule enforces safe development by keeping SKILL.md files concise, using reusable reference documents to maintain readability and prevent overly complex skill definitions.

Trigger patterns include keywords, intent patterns, file paths, and content patterns, allowing skills to activate contextually while enforcing skip conditions to prevent repetitive prompts.

Test skill triggers by adding the skill to skill-rules.json and validating activation patterns through reference-material driven development, which provides concrete testing guidance and structured debugging workflows.

Progressive disclosure allows complex skill rules to be managed through reusable reference documents, keeping the main SKILL.md under 500 lines while preserving detailed implementation guidance.