"Troubleshoot Claude Code extensions and behavior. Triggers on: debug, troubleshoot, not working, skill not loading, hook not running, agent not found."
Resources
3Install
npx skillscat add 0xdarkmatter/claude-mods/claude-code-debug Install via the SkillsCat registry.
About this skill
This skill provides diagnostics and troubleshooting for Claude Code extensions, hooks, and agent behavior. It helps developers resolve issues such as skills failing to load, hooks not executing, or MCP connection errors. It should be used when the CLI behaves unexpectedly or when custom extensions are not activating as intended.
SKILL.md
Claude Code Debug
Troubleshoot extensions, hooks, and unexpected behavior.
Quick Diagnostics
# Enable debug mode
claude --debug
# Check loaded extensions
/hooks # View registered hooks
/agents # View available agents
/memory # View loaded memory files
/config # View current configurationCommon Issues
| Symptom | Quick Check |
|---|---|
| Skill not activating | Verify description has trigger keywords |
| Hook not running | Check chmod +x, run /hooks |
| Agent not delegating | Add "Use proactively" to description |
| MCP connection fails | Test server manually with npx |
| Permission denied | Check settings.json allow rules |
Debug Mode Output
claude --debug
# Shows:
# - Hook execution and errors
# - Skill loading status
# - Subagent invocations
# - Tool permission decisions
# - MCP server connectionsQuick Fixes
Skill Not Loading
# Check structure
ls -la .claude/skills/my-skill/
# Must have: SKILL.md
# Verify YAML frontmatter
head -10 .claude/skills/my-skill/SKILL.md
# Must start/end with ---
# Check name matches directory
grep "^name:" .claude/skills/my-skill/SKILL.mdHook Not Executing
# Make executable
chmod +x .claude/hooks/my-hook.sh
# Test manually
echo '{"tool_name":"Bash"}' | .claude/hooks/my-hook.sh
echo $? # Check exit code
# Verify JSON syntax
jq '.' ~/.claude/settings.jsonAgent Not Being Used
# Check file location
ls ~/.claude/agents/
ls .claude/agents/
# Verify description includes "Use for:" or "Use proactively"
grep -i "use" agents/my-agent.md | head -5
# Explicitly request
# "Use the my-agent agent to analyze this"Validation
# Run all validations
just test
# YAML validation only
just validate-yaml
# Name matching only
just validate-namesOfficial Documentation
- https://code.claude.com/docs/en/hooks - Hooks reference
- https://code.claude.com/docs/en/skills - Skills reference
- https://code.claude.com/docs/en/sub-agents - Custom subagents
- https://code.claude.com/docs/en/settings - Settings configuration
Additional Resources
./references/common-issues.md- Issue → Solution lookup table./references/debug-commands.md- All inspection commands./references/troubleshooting-flow.md- Decision tree
See Also: claude-code-hooks for hook debugging, claude-code-templates for correct structure