Conciseness

The body is tight, imperative, and free of explanations of concepts Claude already knows, but a few rationale sentences in Decision Points ("A swapped or missing normal changes the biological meaning of the calls", "explicitly state the false-positive risk") could be trimmed, matching the efficient-with-minor-trimmable-instances anchor.

Actionability

Two executable command blocks with real script paths and flags (preflight with --emit-install-plan; the Mutect2 runner with --sample-sheet, --germline-resource, --panel-of-normals) plus the sarek runner command give mostly copy-paste-ready guidance, but the somatic_pairs.tsv format is never specified and the sarek command has no example arguments, keeping it below fully-executable.

Workflow Clarity

A clear sequence (confirm inputs → preflight → route → run → outputs) with genuine checkpoints (preflight install plan, "Verify tumor-normal pair metadata before execution", advisory-vs-blocking resource readiness) earns the clear-sequence anchor, but there are no explicit feedback loops for what to do when preflight or the resource check fails, which the top anchor requires.

Progressive Disclosure

Sections are well organized with no dangling references and no bundle files to coordinate, but at roughly 63 lines — above the under-50-line simple-skill exception — the dense Outputs and Decision Points lists and the resource-plan paragraph could be split into a reference file, matching the good-structure-with-minor-gaps anchor.

Specificity

The description lists multiple concrete actions ("pairing, contamination, panel-of-normals, purity, QC, and annotation checks") across the full range of workflow designs and assays ("tumor-normal, tumor-only, WGS, WES, or cancer-panel"), matching the comprehensive-coverage anchor; no gaps are evident within the stated scope.

Completeness

The "what" is clear and concrete (run or plan somatic variant workflows with named checks), but there is no "Use when..." clause or equivalent explicit trigger guidance — "Run or plan" only weakly implies when to use the skill, which caps completeness at 3 per the judging guidelines.

Trigger Term Quality

Natural terms like "tumor-normal", "WGS", "WES", "cancer-panel", "somatic variant", "panel-of-normals", and "purity" are present, but common variations users would say are missing ("SNV/indel", "Mutect2", "matched normal", "VCF"), matching the good-coverage-with-a-few-missing anchor rather than the comprehensive-synonym anchor.

Distinctiveness Conflict Risk

"Somatic" plus tumor/purity terminology carves a mostly distinct niche, but the body itself routes germline requests to a sibling germline skill and broad terms ("WGS", "WES", "QC") carry minor overlap risk with closely related NGS skills, matching the mostly-distinct anchor rather than minimal-conflict.