Conciseness

Nearly every token carries skill-specific knowledge Claude cannot infer (tool names, silent PDB numbering offsets, freesasa RSA quirks, cutoff conventions), with no generic-concept padding. Not 5: the opening paragraph partly restates the frontmatter description, and phrases like 'This is the annotation track that anchors any DMS heatmap…' could be trimmed.

Actionability

Fully executable, copy-paste-ready guidance: exact tool calls with all parameters, the documented return shape ('annotations: List[{position, aa, dist_partner, dist_ligand, rsa, region, is_core, ss_element?}]… yields 168 rows'), a runnable landmark assert, and concrete downstream indexing code. Specific examples cover the common cases.

Workflow Clarity

Five clearly sequenced steps with an explicit validation checkpoint — Step 3 verifies residue numbering via a landmark assert and prescribes the recovery path ('record the offset explicitly… Do not silently rebase positions'). Not 4: the feedback loop (verify → record offset → re-check before any join) is fully explicit.

Progressive Disclosure

No bundle files exist and the skill is a single, well-organized file with clear section headers, tables, and a cross-references table pointing to sibling tools rather than nested files. Not 5: it is a monolithic ~175-line document — the interpretation table and honest-limitations sections are candidates for one-level-deep reference files had a bundle structure been used.

Specificity

Lists multiple concrete actions — 'produce a per-residue annotation table: which residues sit at a binding interface… which line a ligand pocket, which are buried (core) vs solvent-exposed (surface), and optionally secondary structure' — with comprehensive, domain-specific coverage. Not 4: there are no minor gaps in the action list.

Completeness

Explicitly answers both: the 'what' (a per-residue annotation table with interface/pocket/core-surface/secondary-structure classifications) and the 'when' ('Use when you need to anchor a variant-interpretation or DMS analysis to the protein's actual physical context') with a concrete trigger clause. Not 4: neither half could be more explicit.

Trigger Term Quality

Good natural keyword coverage: 'PDB structure', 'binding interface', 'ligand pocket', 'DMS heatmap', 'variant-interpretation', 'SAE feature drops' — terms the target user would actually say. Not 5: misses common synonyms/variations such as 'protein structure', 'active site', or 'mutation', so a few natural trigger phrases are absent.

Distinctiveness Conflict Risk

Clear niche — per-residue structural annotation of a PDB chain for DMS/variant interpretation — with distinctive triggers (PDB, per-residue, DMS heatmap, SAE feature drops) that no generic skill would match. Minimal conflict risk.