Conciseness

The body is dense with non-obvious, version-pinned specifics (0.9 API corrections, renamed CFL/forcing fields, restart CLI safety warnings) and contains no concept-explanation padding. It falls short of a 5 because time-sensitive detail (verification dates like 2026-09-30/2026-10-01, the verification-coverage inventory, and the lengthy citation procedure) is not confined to a deprecated/old-patterns section and could be trimmed.

Actionability

Guidance is fully executable: copy-paste-ready uv lock/sync commands, working parameter-setting code using real 0.9 field paths, concrete bundled-tool invocations with flags, and load/plot snippets covering the common analysis cases. This matches the anchor for copy-paste-ready commands covering common cases.

Workflow Clarity

The 9-step required workflow sequences the process with explicit validation checkpoints (bundled validator/estimator at step 4, pilot inspection at step 6), a refine-feedback loop (step 7), hard stop conditions when assumptions are missing, and a scientific acceptance-gate checklist. This matches the anchor for explicit validation steps, feedback loops, and checklists.

Progressive Disclosure

The body is a well-organized overview that defers detail to six clearly signaled references (each section ends with a "See [X](references/X)" pointer), all of which exist and contain no nested second-level references; bundled scripts are listed and real. This matches "clear overview with well-signaled one-level-deep references; easy navigation".

Specificity

The description lists five concrete lifecycle actions ("Plans, configures, inspects, restarts, and analyzes") with scope qualifiers ("bounded ... simulations with explicit numerical-validity and HPC safety checks"), comprehensively covering the workflow without vague filler. It exceeds the score-4 anchor ("several specific actions; minor gaps") because the actions span the entire plan-to-analysis lifecycle.

Completeness

Both questions are answered explicitly: the first sentence states what the skill does, and "Use for FluidSim solver selection, parameter review, FFT/MPI setup, output diagnostics, or restart compatibility" gives concrete when-to-use triggers. It is not the 4 anchor because the 'when' clause is fully explicit and itemized rather than improvable.

Trigger Term Quality

Natural trigger phrases users would say are present ("FluidSim solver selection", "parameter review", "FFT/MPI setup", "output diagnostics", "restart compatibility"), but a few common synonyms are missing — e.g., the "CFD" acronym itself (only the spelled-out "computational-fluid-dynamics" appears) and terms like "turbulence" or "Navier-Stokes". This matches "good keyword coverage; a few natural terms missing" rather than the comprehensive-synonym coverage of a 5.

Distinctiveness Conflict Risk

The skill occupies a clear niche (the named FluidSim framework) with distinct triggers, so overlap with other skills is minimal; the broad phrase "computational-fluid-dynamics" is anchored to FluidSim throughout. It fits "clear niche with distinct triggers; minimal conflict risk".