Side-by-side comparison of two Model Context Protocol servers — install paths, tools, quality signals, and directory engagement so you can pick the right one for Claude, Cursor, and other MCP clients.
Chemistry toolbox computed from authoritative data: molecular weight / molar mass of any formula (nested groups, isotope labels, propagated NIST uncertainties, percent composition), isotope-distribution mass spectra (m/z peaks for a given charge), and name⇆formula lookup with isomer resolution. Element masses from the NIST Atomic Weights and Isotopic Compositions database; offline and deterministic, with an optional on-by-default online fallback (PubChem/Wikidata/EPA CompTox) that can be disabled. uvx mcp-molecules.
Semantic search over 600k+ CS/AI papers with citation-graph traversal, full-text extraction, embeddings, and BibTeX export. Works anonymously or with a free key. Install: npx scholar-feed-mcp init.