Conciseness

Every sentence carries instruction or a functional scope guardrail ("it does not install benchmark dependencies or run paid evaluations merely by being added to a host"), with no concept explanations or padding. Lean and fully assuming of competence, matching anchor 5; anchor 4 would require something that could be trimmed, and nothing here can.

Actionability

Provides concrete pointers (the AgentPilot repo URL, "arena/README.md", "agentpilot/integrations/arena/README.md") but zero executable commands; "Install that component's environment" and "Use the selected formal benchmark runner" defer all execution specifics to external docs, leaving key details missing. This matches anchor 3 rather than anchor 4, which requires concrete code or commands with only minor gaps.

Workflow Clarity

A clear ordered sequence (obtain checkout, read docs, infer benchmark/method, install and verify, run, report) with an explicit pre-launch checkpoint ("verify its task data, model configuration, execution dependencies, and evaluator before launch") and reporting requirements. Falls short of anchor 5 because there is no error-recovery feedback loop or checklist for when verification fails; exceeds anchor 3 because the validation checkpoint is explicit, not missing or implicit.

Progressive Disclosure

The body is roughly 10 lines with no bundle files (references/, scripts/, assets/ are absent) and appropriately delegates all detail to clearly signaled, one-level-deep external docs (arena/README.md and agentpilot/integrations/arena/README.md). Under the simple-skill guidance this matches anchor 5: nothing is inlined that belongs elsewhere and navigation is unambiguous.

Specificity

Names concrete actions ("Set up or run RSI Arena benchmark evaluations") and specific benchmarks ("AIME, Terminal-Bench"), giving several specific elements with only minor coverage gaps. Not 5 because coverage is not comprehensive (only two core verbs), not 3 because it goes well beyond naming the domain with multiple concrete, named items.

Completeness

Explicitly answers both: what ("Set up or run RSI Arena benchmark evaluations from HKUDS AgentPilot") and when ("Use for AIME, Terminal-Bench, and comparing improvement methods") with concrete trigger phrases. The 'when' is explicit and specific, matching anchor 5 rather than anchor 4 where the trigger guidance would be weaker or less concrete.

Trigger Term Quality

Includes natural, user-sayable terms like "AIME", "Terminal-Bench", "RSI Arena", "benchmark evaluations", and "comparing improvement methods". A few natural variations are missing (e.g., other RSI Arena benchmarks or common synonyms like "evals"), so it does not reach comprehensive anchor 5 but clearly exceeds anchor 3's partial coverage.

Distinctiveness Conflict Risk

Occupies a clear niche (RSI Arena benchmark evaluations from HKUDS AgentPilot) and explicitly disambiguates the closely related sibling skill ("use agentpilot for the unified RSI entry or ordinary coding work"), actively minimizing conflict risk. This matches anchor 5's clear niche with distinct triggers; anchor 4 would leave the overlap risk unaddressed.