Conciseness

Mostly dense and useful — argument tables, executable commands, sample CSV, error tables — with little explanation of concepts Claude already knows. Not 5 because the "Implementation Checklist" (10 checked dev boxes), the "Last updated: 2026-04-27 | Version: 2.1.0" stamp, and the unresolved optparse "root fix" TODO note are internal metadata that could be trimmed.

Actionability

Copy-paste-ready bash commands with a complete argument table (defaults, types), four worked examples, sample input data, and an error-code-to-solution table. Not 5 because several executable examples reference bundle paths that do not exist ("scripts/install_dependencies.R", "tests/data/sample_clinical_survival_data.csv", "tests/run_smoke_test.R", "tests/run_smoke_test.sh"), so those commands fail as written.

Workflow Clarity

The four-step workflow is clearly sequenced with explicit validation in steps 1-2 (column presence, complete-case filtering, rejection of non-positive times, invalid coding, <30 samples, <10 events), and the error-handling table provides a feedback loop ("IF error persists, READ: references/troubleshooting.md"). Not below 5 since checkpoints and recovery paths are explicit.

Progressive Disclosure

The "When to Read External Files" table is a well-signaled, one-level-deep map and all four of its targets exist in the bundle (references/algorithm.md, scripts/main.R, references/troubleshooting.md, references/cli-guide.md). Not 5 because the body also references nonexistent paths (install_dependencies.R, tests/*) and inlines dev-metadata (checklist, version stamp) that belongs elsewhere.

Specificity

Names concrete actions — "fitting a Cox model", "generating bootstrap calibration curves at one or more prediction horizons", "from a clinical CSV file" — plus an explicit exclusion list. Not 5 because it omits capabilities the skill actually has (exporting statistics and a PDF visualization); not 3 because it lists several specific actions rather than only 1-2.

Completeness

Explicitly answers both: the "what" ("fitting a Cox model and generating bootstrap calibration curves... from a clinical CSV file") and the "when" ("Use when assessing how well a survival model's predicted probabilities agree with observed outcomes"), with concrete trigger phrasing and a NOT-for list. Matches the anchor-5 pattern.

Trigger Term Quality

Good natural-term coverage: "calibration curve", "Cox model", "survival model", "predicted probabilities", "clinical CSV file", plus boundary terms ("nomogram", "ROC", "decision-curve analysis"). Not 5 because common variations like "calibration plot", "bootstrap", or "predicted vs. observed survival" are missing.

Distinctiveness Conflict Risk

Clear niche — bootstrap calibration of survival/Cox models from clinical CSV data — with an explicit "NOT for: nomogram construction, univariate Cox screening, ROC analysis, or decision-curve analysis" boundary that cleanly separates it from the closest sibling skills.