Conciseness

The body is dense and assumes domain competence (methods are named with thresholds rather than tutored), but has minor redundancy: the opening line repeats the frontmatter summary ('Always outputs four workload configurations and a recommended primary plan'), the trailing 'Reference Files' table duplicates the inline Step 4 pointers already given, and fault-tolerance rules overlap Hard Rules 6–8. Anchor 4 ('efficient; minor instances... that could be trimmed') fits better than 5's 'every token earns its place'.

Actionability

Guidance is fully executable: concrete thresholds ('p < 5×10⁻⁸, LD clumping r² < 0.001 / 10,000 kb', 'F > 10', 'PP.H4 > 0.8'), a complete copy-paste-ready TwoSampleMR R template with the available_outcomes() lookup pattern, and specific fallback methods ('LIML, sisVIVE'). The EXAMPLE-ID placeholders are explicitly justified with inline comments, and per the scoring notes the instruction-style planning guidance is equally concrete.

Workflow Clarity

Steps 1–9 are clearly sequenced with explicit validation checkpoints and feedback loops: 'If IV count falls below 3: warn the user that MR is not feasible', 'If F-statistic < 10 for all IVs: do not proceed with IVW as primary', 'Confirm this fits within any stated time constraints before recommending', and a 'Revision strategy if first-pass findings fail'. This matches the anchor-5 pattern of explicit validation plus error-recovery loops.

Progressive Disclosure

Both referenced files (references/iv_benchmarks.md, references/gwas_databases.md) exist, contain exactly the promised lookup tables, and are one level deep. They are clearly signaled inline in Step 4 with '→' arrows and summarized in a 'Reference Files' table with a 'Used In' step column, while bulky per-exposure-class data is appropriately split out of the overview.

Specificity

The description enumerates multiple concrete actions and outputs — 'Generates complete two-sample Mendelian randomization (MR) research designs' and 'Always outputs four workload configurations (Lite / Standard / Advanced / Publication+) with a recommended primary plan, step-by-step workflow, figure plan, validation strategy, minimal executable version, and publication upgrade path' — giving comprehensive, specific coverage in third-person voice. Not 4, because no deliverable gaps remain that would justify 'minor gaps in coverage'.

Completeness

It explicitly answers both questions: what ('Generates complete two-sample MR research designs... Always outputs four workload configurations...') and when ('Use when users want to design, plan, or build a study using two-sample MR to test causal relationships') with a list of concrete trigger phrases. This exactly matches the anchor-5 pattern of what + explicit when with concrete trigger phrases.

Trigger Term Quality

Trigger coverage is comprehensive and natural: 'design a two-sample MR study', 'build a publishable MR paper', 'test whether this biomarker causally affects this disease', 'screen multiple exposures with MR', 'bidirectional MR design', 'I want to study X and Y using MR'. Both the full domain term and the common abbreviation (MR) appear, plus screening, bidirectional, and publication-oriented phrasings users would actually say.

Distinctiveness Conflict Risk

The skill occupies a clear niche (two-sample MR study design from GWAS summary statistics) with distinct, domain-specific triggers; it would not fire for generic document, code, or statistics skills. The only conceivable overlap is with a hypothetical general MR-execution skill, which is minimal.