Conciseness

Mostly efficient operational content (tool signatures, gotchas, formulas), but the Trimmomatic discarded-reads rule is stated twice (top-of-mind rule plus the full FASTQ section), wobble rules appear in two places, and sections teach known biology ('Kinase domain = phosphorylation activity; SH2 domain = phosphotyrosine binding', alpha-helix 3.6 res/turn). Not 2 because the bulk is skill-specific knowledge Claude cannot know; not 4 because the duplication and textbook padding are more than minor.

Actionability

Fully executable throughout: exact tool parameters with return shapes ('NCBIGene_search: term (string REQUIRED, format ...)'), a runnable awk one-liner ('samtools depth -a alignment.bam | awk ...'), copy-paste script invocations ('sequence_tools.py --type count_region --accession P24046 --start 318 --end 440 --residue C'), and step-by-step recipes covering common cases. Not 4 — there are no meaningful gaps in executability.

Workflow Clarity

A clear phase sequence (Phase 1 gene ID resolution → Phase 6 variant context), a Rule Zero pre-check ordering, per-phase gotchas, fallbacks, and 'LOOK UP DON'T GUESS' verification guidance. Not 5: the entry sequence is fragmented (two preamble rules before the actual overview) and verification checkpoints are advisory rather than explicit validate-then-proceed steps; not 3 because sequencing and checkpoints are substantially present.

Progressive Disclosure

The four bundled scripts are real, clearly signaled, and invoked with full paths, but there is no references/ directory — the ~380-line body inlines a tool parameter reference table, interpretation frameworks, and peptide/foldamer chemistry that belong in separate reference files. Anchor 3 ('content that should be separate is inline'); not 4 because a large reference-grade section is monolithic in SKILL.md.

Specificity

The description lists multiple concrete actions — 'gene/protein sequence retrieval (NCBI, Ensembl, UniProt), nucleotide/protein search, ortholog discovery, and FASTQ QC + alignment workflows (Trimmomatic, BWA, samtools, coverage depth)' — with named tools and databases, comprehensively covering the skill's capabilities. Not 4, since there are no meaningful gaps in the action list.

Completeness

It explicitly answers both what ('gene/protein sequence retrieval ... FASTQ QC + alignment workflows') and when ('Use for sequence retrieval, sequence comparison, FASTQ QC analysis, and read alignment pre-processing') with concrete trigger phrases. Not 4, since the 'when' clause is explicit rather than only weakly specific.

Trigger Term Quality

'sequence retrieval', 'sequence comparison', 'FASTQ QC analysis', and 'read alignment pre-processing' are natural phrases users would say, backed by tool names (Trimmomatic, samtools). Not 5 because 'ortholog' — a headline capability — is absent from the 'Use for' clause and there are no file extensions (.fastq); not 3 because keyword coverage is broad and natural rather than merely 'some relevant keywords'.

Distinctiveness Conflict Risk

Distinct niche triggers like 'Trimmomatic', 'BWA', 'samtools', 'UniProt', and 'FASTQ QC' minimize conflict risk, but the broad 'biological sequence analysis' umbrella spanning both retrieval and read-QC pipelines could overlap with sibling bioinformatics skills (e.g., an RNA-seq or protein-analysis skill). Not 5 for that residual overlap risk.