Each tool maps to a distinct operation in the RAG lifecycle: rag_search retrieves, rag_open expands context around a hit, rag_index rebuilds, and rag_stats reports status. Descriptions explicitly cross-reference each other (rag_open consumes ids from rag_search; rag_index notes the full-rebuild CLI alternative), leaving no overlap.

All four tools use the same rag_ prefix plus a short lowercase verb (open, index, stats, search), fully consistent snake_case with no stray styles. The namespace prefix also makes the tools instantly recognizable as belonging to one server.

Four tools is on the thin side, but each covers a genuinely needed verb (search, fetch-context, build, inspect) with no filler. It is well-scoped for a local index server, though one or two more operations (e.g. source listing or pruning) would not feel redundant.

The read path (search → open for context) and the maintenance path (index → stats) are both covered, which handles the core recall and rebuild workflows. Minor gaps remain: no way to remove or exclude stale content, and no listing of which sources exist beyond the aggregate counts in rag_stats.