Conciseness

The 47-line body is lean, assumes domain competence, and wastes no tokens explaining known concepts — "Do not compare relax and SP outputs as if they were the same screening stage" is exactly the kind of non-obvious guidance the rubric rewards. It falls short of 5 due to minor redundancy: Quick Start steps 2-3 restate Workflow sections 1-2, and the tool list appears in both frontmatter metadata and a separate 'Suggested tools' section.

Actionability

Concrete guidance exists — named tools ("mace_relax_batch", "mace_sp_batch"), named parameters ("model", "head", "dispersion", "relax_lattice"), explicit constraints ("Keep output_root outside input_dir"), and named return fields ("batch_state_rel", "batch_summary_rel") — but there are no executable invocations: no example tool call, no argument shapes, and no concrete keep/drop rule (the Output Contract only requires returning one without defining what a good rule is). This matches anchor 3 ('some concrete guidance but incomplete; missing key details') better than anchor 4, which expects concrete code or commands with only minor gaps.

Workflow Clarity

The Quick Start gives a coherent 4-step sequence, and Workflow section 3 supplies genuine validation checkpoints for the batch operation ("Use collected evidence, not launch success alone"; "inspect those before deciding to rerun"), so the batch-operations cap does not apply. It is not 5 because the keep/drop decision — the workflow's terminal step — is left implicit, and there is no validate-then-retry loop spelling out when a rerun is warranted versus a partial-output salvage.

Progressive Disclosure

There are no bundle files (no references/, scripts/, or assets/ directories), and the body is under 50 lines with no content that needs offloading, so per the rubric's simple-skill guidance well-organized sections alone warrant a 5. Sections (Overview, Quick Start, Suggested tools, Workflow, Method-critical defaults, Output Contract, References) are clearly headed, one level deep, and easy to navigate; the 'References' section points to a sibling skill (vasp-input-preparation) as a handoff boundary, not a nested file.

Specificity

"MACE-based rapid screening and relaxation loops before DFT, including candidate pruning and handoff criteria" names the domain and several actions (screening, relaxation, pruning, handoff), which would fit anchor 4, but it opens with the second-person imperative "Use this skill for..." rather than third-person voice, so per the rubric's voice penalty the score is reduced by 1. It is not anchor 2 because the actions go beyond minimal/generic domain naming.

Completeness

Both parts are present: what ("MACE-based rapid screening and relaxation loops... candidate pruning and handoff criteria") and when ("before DFT", framed by the explicit trigger "Use this skill for..."). It is not 5 because the 'when' is a single timing condition rather than concrete trigger phrases (e.g. 'when the user asks to pre-screen candidates before VASP'); it is not 3 because the trigger guidance is explicit, not merely implied.

Trigger Term Quality

Natural terms a computational-materials user would say are present — "MACE", "screening", "relaxation", "DFT", "candidate pruning" — giving good keyword coverage. It is not 5 because common synonyms and adjacent phrasings users might use (e.g. "VASP", "machine-learned potential", "pre-relax", "cheap relaxation") are missing.

Distinctiveness Conflict Risk

"MACE-based rapid screening and relaxation loops before DFT" carves out a clear niche with distinct triggers (MACE, pre-DFT screening, candidate pruning); a user naming these terms is almost certainly asking for this skill. Only trivial overlap risk with a general DFT-orchestration skill keeps it from being ambiguous, and it matches the anchor-5 example's clarity.