tools-only Marketplace Visibility Investigation: mermaidjs-v11 & context-engineering
Date: 2025-12-30 Investigator: debugger subagent ID: a3b2656
Executive Summary
Issue: User reports "mermaidjs-v11" and "context-engineering" skills not visible when installing from plugins marketplace.
Root Cause:
- mermaidjs-v11: Skill EXISTS and IS properly registered in specialized-tools plugin. NO configuration issue found.
- context-engineering: Skill does NOT EXIST in repository - never created/added.
Impact:
- mermaidjs-v11: Should be installable via
specialized-tools@claudekit-skills- may be UI discovery issue - context-engineering: Cannot be installed - skill doesn't exist
Technical Analysis
Repository Structure
claudekit-skills/
├── .claude-plugin/
│ └── marketplace.json # Root marketplace config
├── .claude/skills/ # 28 actual skill directories
│ ├── mermaidjs-v11/ ✓ EXISTS
│ ├── sequential-thinking/ ✓ EXISTS
│ └── ... (26 others)
└── plugins/ # Plugin categories
├── specialized-tools/
│ ├── .claude-plugin/
│ │ └── plugin.json # Plugin metadata
│ └── skills/
│ ├── mermaidjs-v11 -> ../../../.claude/skills/mermaidjs-v11 ✓
│ └── sequential-thinking -> ../../../.claude/skills/sequential-thinking ✓
└── ... (11 other plugins)
Marketplace Configuration Analysis
Root marketplace.json (.claude-plugin/marketplace.json):
{
"plugins": [
{
"name": "specialized-tools",
"source": "./plugins/specialized-tools",
"description": "Specialized skills: sequential-thinking (step-by-step reasoning), mermaidjs-v11 (diagram generation)",
"version": "1.0.0",
"keywords": ["diagrams", "reasoning", "visualization"],
"category": "productivity"
}
]
}
✓ mermaidjs-v11 IS listed in description ✓ Plugin registered correctly
Plugin metadata (plugins/specialized-tools/.claude-plugin/plugin.json):
{
"name": "specialized-tools",
"description": "Specialized skills for sequential reasoning and Mermaid diagram generation",
"version": "1.0.0",
"author": {"name": "ClaudeKit", "email": "[email protected]"},
"repository": "https://github.com/mrgoonie/claudekit-skills"
}
✓ Mentions Mermaid diagram generation ✓ Properly configured
Skill File Structure
mermaidjs-v11 (/.claude/skills/mermaidjs-v11/):
mermaidjs-v11/
├── SKILL.md ✓ Main skill definition with frontmatter
└── references/ ✓ Supporting docs
Frontmatter metadata:
---
name: mermaidjs-v11
description: Create diagrams and visualizations using Mermaid.js v11 syntax...
---
✓ Properly formatted skill definition
Symlink verification:
plugins/specialized-tools/skills/mermaidjs-v11
-> ../../../.claude/skills/mermaidjs-v11 ✓
Evidence: context-engineering Does NOT Exist
Search results:
# grep -r "context-engineering" /Users/duynguyen/www/claudekit/claudekit-skills/
# (no output)
# find ... -name "context-engineering*" -type f -o -name "context-engineering*" -type d
# (no output)
✗ No skill directory ✗ No references in any config files ✗ No mentions in documentation ✗ Never existed in repository
Comparison: Working vs Reported Skills
Working skills (e.g., frontend-design, ai-multimodal):
- Directory:
.claude/skills/{skill-name}/ - File:
SKILL.mdwith frontmatter - Symlink:
plugins/{category}/skills/{skill-name}->.claude/skills/{skill-name} - Registered: Listed in plugin description
mermaidjs-v11 (reported as missing): ✓ Has directory ✓ Has SKILL.md with frontmatter ✓ Has symlink ✓ Listed in plugin description → Structure IDENTICAL to working skills
context-engineering (reported as missing): ✗ No directory ✗ No files ✗ No registration → Never existed
Installation Command Analysis
Expected installation:
/plugin marketplace add mrgoonie/claudekit-skills
/plugin install specialized-tools@claudekit-skills
This SHOULD install:
- sequential-thinking ✓
- mermaidjs-v11 ✓ (properly configured)
Skill Discovery Count
# Total skill directories in .claude/skills/
29 directories (includes subdirectories like debugging/*, problem-solving/*)
# Total skill definition files
38 SKILL.md files (includes nested skills)
# Plugin categories
12 plugins in marketplace.json
Root Cause Summary
mermaidjs-v11
Configuration: ✓ CORRECT Structure: ✓ VALID Registration: ✓ PRESENT Symlink: ✓ WORKING
Hypothesis: Issue likely in:
- Claude Code UI not discovering skills correctly from plugin structure
- Cache/refresh issue in marketplace UI
- Skill file format expectation mismatch (SKILL.md vs skill.md)
Evidence against configuration issue:
- Identical structure to working skills (frontend-design, ai-multimodal)
- Properly registered in marketplace.json
- Valid SKILL.md frontmatter format
- Working symlink chain
context-engineering
Status: ✗ DOES NOT EXIST Cause: Skill was never created/added to repository
Evidence:
- No directory in
.claude/skills/ - No references in any JSON configs
- No documentation mentions
- grep/find returned zero results
Supporting Evidence
File paths verified:
- Root config:
/Users/duynguyen/www/claudekit/claudekit-skills/.claude-plugin/marketplace.json - Plugin config:
/Users/duynguyen/www/claudekit/claudekit-skills/plugins/specialized-tools/.claude-plugin/plugin.json - Skill location:
/Users/duynguyen/www/claudekit/claudekit-skills/.claude/skills/mermaidjs-v11/ - Symlink:
/Users/duynguyen/www/claudekit/claudekit-skills/plugins/specialized-tools/skills/mermaidjs-v11
Symlink resolution:
$ readlink plugins/specialized-tools/skills/mermaidjs-v11
../../../.claude/skills/mermaidjs-v11 ✓ VALID
Recommended Investigation Steps
- Test marketplace installation in clean environment
- Check Claude Code logs for skill discovery errors
- Verify marketplace cache/refresh behavior
- Compare skill.md vs SKILL.md naming expectations
- Test if skills appear after manual plugin installation
Unresolved Questions
- Why does mermaidjs-v11 not appear in UI if config is correct?
- Is there a skill discovery cache that needs clearing?
- Does Claude Code expect lowercase
skill.mdinstead ofSKILL.md? - Was context-engineering mentioned in error or planned but not implemented?