Conciseness

The body is dense and skill-specific (numbering offsets, RSA quirks, cutoff conventions) with almost no padding or explanation of things Claude already knows, but a few spots could be tightened — e.g. the interpretation table's 'Common functional role' column restates standard protein biology, and the intro paragraph duplicates the frontmatter description almost verbatim.

Actionability

Every step ships copy-paste-ready calls with full argument signatures ('Structure_annotate_per_residue(pdb_id="6VJJ", target_chain="A", ...)'), the documented return shape, an executable landmark assert, and concrete downstream recipes keyed on exact field names ('by_pos[X]["region"] in ("ligand", "both")').

Workflow Clarity

A clear five-step sequence with an explicit validation checkpoint (Step 3: verify numbering with a UniProt landmark before joining) and an error-recovery path ('If the landmark mismatches, record the offset explicitly ... Do not silently rebase positions'), plus an honest-limitations section covering failure modes.

Progressive Disclosure

No bundle files exist, and the single-file body is well-sectioned with clear headers (inputs, workflow, interpretation table, limitations, cross-references) making it easy to navigate. At ~180 lines, material like the cross-references table and detailed limitations could arguably move to a reference file, so minor organization gains remain.

Specificity

The description enumerates multiple concrete outputs — 'which residues sit at a binding interface (vs a partner chain), which line a ligand pocket, which are buried (core) vs solvent-exposed (surface), and optionally secondary structure' — comprehensive and fully concrete coverage of the skill's per-residue annotation capability.

Completeness

It clearly answers 'what' (produce a per-residue annotation table with the enumerated classifications) and 'when' explicitly: 'Use when you need to anchor a variant-interpretation or DMS analysis to the protein's actual physical context.'

Trigger Term Quality

Strong natural terms within the niche ('PDB structure', 'binding interface', 'ligand pocket', 'buried', 'solvent-exposed', 'DMS heatmap', 'variant-interpretation'), but a few common phrasings a user would naturally say are missing (e.g. 'map variants onto the structure', 'surface accessibility', file-style terms like '.pdb').

Distinctiveness Conflict Risk

A clear niche (structural annotation from a PDB for DMS/variant interpretation) with mostly distinct triggers, but the 'DMS heatmap' and 'SAE feature drops' framing overlaps with the referenced downstream consumer skill 'tooluniverse-residue-functional-mechanism-interpretation', creating minor mis-trigger risk.