Claude-skill-registry-data mcp-tool-selection

Decision rules for when to use MCP Qdrant-Indexer semantic search vs grep/literal file tools. Use this skill when starting exploration, debugging, or answering "where/why" questions about code.

install

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry-data

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry-data "$T" && mkdir -p ~/.claude/skills && cp -r "$T/data/mcp-tool-selection" ~/.claude/skills/majiayu000-claude-skill-registry-data-mcp-tool-selection && rm -rf "$T"

manifest: data/mcp-tool-selection/SKILL.md

source content

MCP Tool Selection Rules

Core principle: MCP Qdrant-Indexer tools are primary for exploring code and history. Start with MCP for exploration, debugging, or "where/why" questions; use literal search/file-open only for narrow exact-literal lookups.

Use MCP Qdrant-Indexer When

Exploring or don't know exact strings/symbols
Need semantic or cross-file understanding (relationships, patterns, architecture)
Want ranked results with surrounding context, not just line hits
Asking conceptual/architectural or "where/why" behavior questions
Need rich context/snippets around matches

Use Literal Search/File-Open Only When

Know exact string/function/variable or error message
Only need to confirm existence or file/line quickly (not to understand behavior)

Grep Anti-Patterns (DON'T)

grep -r "auth" .        # → Use MCP: "authentication mechanisms"
grep -r "cache" .       # → Use MCP: "caching strategies"  
grep -r "error" .       # → Use MCP: "error handling patterns"
grep -r "database" .    # → Use MCP: "database operations"

Literal Search Patterns (DO)

grep -rn "UserAlreadyExists" .      # Specific error class
grep -rn "def authenticate_user" .  # Exact function name
grep -rn "REDIS_HOST" .             # Exact environment variable

Quick Decision Heuristic

Question Type	Tool
"Where is X implemented?"	MCP `repo_search`
"Who calls this and show code?"	MCP `symbol_graph` (hydrated w/ snippets)
"Callers of callers? Multi-hop?"	MCP `neo4j_graph_query` (transitive_callers, depth=2)
"What breaks if I change X?"	MCP `neo4j_graph_query` (impact, depth=2)
"Circular dependencies?"	MCP `neo4j_graph_query` (cycles)
"How does authentication work?"	MCP `context_answer`
"High-level module overview?"	MCP `info_request` (with explanations)
"Does REDIS_HOST exist?"	Literal grep
"Why did behavior change?"	`search_commits_for` + `change_history_for_path`

If in doubt → start with MCP