Conciseness

The body carries genuinely valuable non-obvious content (quantified minimums, decision trees, evidence grading, Rule Zero), but pads it with textbook concepts Claude already knows — e.g. 'Peptide mass fingerprinting (PMF): Intact protein digested → measured peptide masses compared against theoretical digest of all database proteins' and 'PTMs (phosphorylation, ubiquitination, acetylation, glycosylation) add biological complexity beyond protein abundance' — and repeats the n<3 replicate rule in three sections, fitting 'mostly efficient but includes some unnecessary explanation'.

Actionability

Concrete elements exist (the `tu run read_executed_notebook` command, named tools like limma/DEP/MSstats/QRILC, quantified cutoffs, tool call names like `proteins_api_search`), but there is no executable analysis code for any phase and the detailed procedures are delegated to PHASE_DETAILS.md, which does not exist in the bundle — so the key execution detail layer is missing, matching 'some concrete guidance but incomplete; missing key details'.

Workflow Clarity

Rule Zero provides an explicit gating condition ('Only follow this skill's re-analysis recipe below if none of the above exist') and the 8-phase tree is clearly sequenced with QC as Phase 1 and Quantified Minimums acting as acceptance criteria, matching 'clear sequence with most checkpoints present; minor validation gaps' — the QC pass/fail gates between phases are implicit rather than explicit, keeping it below 5.

Progressive Disclosure

Although SKILL.md is well-sectioned, its central pointer — 'See [PHASE_DETAILS.md](PHASE_DETAILS.md) for detailed procedures per phase' — references a file that is absent from the bundle (no references/ or other bundle files exist), so navigation dead-ends exactly where the detail should live; this matches the anchor-2 failure of the content split rather than the merely imperfect signaling of 3.

Specificity

The description lists multiple specific concrete actions — 'protein identification, quantification (LFQ, TMT, iTRAQ), differential expression (tumor vs normal, treatment vs control), PTM identification, and pathway enrichment' — covering the core proteomics tasks comprehensively with method-level specifics, matching the top anchor rather than the 'minor gaps' anchor at 4.

Completeness

It explicitly answers both 'what' (identification, quantification, differential expression, PTM, pathway enrichment) and 'when' via a concrete 'Use when you have proteomics MS output, asking about protein abundance differences, or doing systems-level proteomic interpretation' clause, exactly matching the anchor-5 pattern; the 'when' is fully explicit, not merely present as at 4.

Trigger Term Quality

Good natural keyword coverage ('proteomics MS output', 'protein abundance differences', 'tumor vs normal', 'pathway enrichment'), but common user phrasings like tool/format names (e.g. 'MaxQuant output') and synonyms like 'phosphoproteomics' are missing, so it fits 'good keyword coverage; a few natural terms missing' rather than the comprehensive-synonym coverage of 5.

Distinctiveness Conflict Risk

The mass-spec proteomics niche is mostly distinct with domain-specific triggers, but 'pathway enrichment on protein lists' and 'systems-level proteomic interpretation' create minor overlap risk with general gene-enrichment and multi-omics skills, fitting 'mostly distinct; minor overlap risk' rather than the minimal-conflict profile of 5.