Conciseness

Mostly efficient tool-specific reference material (argument defaults, error codes, input rules) that Claude cannot know otherwise, but roughly twenty rows of plotting cosmetics (label_*, line_*, point_*, mapping_*) and a 'placeholder retained for compatibility' argument inflate the token budget and could be trimmed or moved to the CLI reference. Not 3, since there is little conceptual over-explanation and the padding is limited to the argument table.

Actionability

The Usage and Testing sections give fully executable Rscript commands and the argument table is complete, but the smoke test cites 'tests/data/gene_list.csv' and the default 'references/string_cache' directory, neither of which exists in the bundle, so those commands fail as written. Not 5 because executable commands referencing missing bundle paths are not copy-paste runnable.

Workflow Clarity

This is a simple single-command CLI skill and the single action is unambiguous: a complete run command, a plot-only regeneration path, an expected-outputs checklist after each test, and an error-code table mapping each failure to a cause and fix form an explicit feedback loop. The simple-skill exception applies.

Progressive Disclosure

The 'When to Read External Files' table gives clear, one-level-deep navigation to real bundle files (algorithm.md, cli-guide.md, troubleshooting.md, scripts/main.R), but one of its five rows ('tests/data/') does not exist in the bundle, and the bulky full argument table overlaps content that the referenced cli-guide.md could carry. Not 3, since structure and signaling are otherwise good.

Specificity

The description lists multiple concrete actions ('build a protein-protein interaction network', 'export node and edge tables', 'render a reproducible PDF network plot') with comprehensive coverage, but 'Use when you need a standardized R CLI workflow' is second-person voice, which the judging guidelines penalize by reducing the specificity score by 1.

Completeness

It explicitly answers both what ('build a... network... export node and edge tables, and render a reproducible PDF network plot') and when ('Use when you need a standardized R CLI workflow to build...'), matching the anchor with concrete trigger phrases; the additional negative boundary clause reinforces the when.

Trigger Term Quality

Natural trigger phrases like 'protein-protein interaction network', 'STRING', 'gene list', and 'network plot' are present, but the widely used synonym 'PPI' (the skill's own name) is never mentioned, leaving a few natural user terms missing. Not 3, since keyword coverage is strong rather than merely 'some relevant keywords'.

Distinctiveness Conflict Risk

It carves out a clear niche (offline STRING-based PPI networks) and explicitly excludes adjacent domains ('NOT for online API fetching, arbitrary graph databases, multi-omics integration, or non-STRING interaction sources'), minimizing conflict risk.