Conciseness

The body is dense and fluff-free — no explanation of concepts Claude already knows, every sentence carries a constraint or instruction. The pinned version ("The selected published go-authcrunch v1.3.11") is time-sensitive information outside a deprecated/old-patterns section, which per the rubric warrants a minor penalty from the lean anchor 5.

Actionability

Fully executable guidance throughout: two copy-paste-ready caddyfile blocks, a bash test command, a path/method/behavior routing table, exact constants (300-second lifetime, 4 KiB bound, 1024 per portal, eight per IP, cookie attributes), and named test files. Specific examples cover the common configuration and verification cases.

Workflow Clarity

The sections follow a coherent sequence — configuration, routing, identity/lifecycle, then an explicit "Acceptance and validation" section with a focused test command and `make ci-check` as the full gate. It falls short of anchor 5 because there is no feedback loop for failure recovery and the sequence is implied by section order rather than explicit steps.

Progressive Disclosure

No bundle files exist, and the single-file body is well organized into four clear sections with no nested or buried references. The detailed acceptance-test inventory (~25 lines enumerating test scenarios) is content that could live in a separate reference file, which keeps it at the good-structure-with-minor-gaps anchor rather than anchor 5.

Specificity

The description lists several concrete capabilities — "Configure and verify optional cross-device portal login, QR activation, explicit approval, browser binding, cancellation, and lifecycle through Caddy" — with named, specific feature areas rather than vague language. Minor gaps: "lifecycle" is abstract, and routing/testing coverage from the body is not reflected, so it sits just below the comprehensive anchor 5.

Completeness

The "what" is clear (configure and verify cross-device login, QR activation, approval, binding, cancellation, lifecycle), but there is no "Use when..." clause or equivalent trigger guidance; the second sentence about ownership is a boundary statement, not a "when". Per the rubric guideline, a missing explicit trigger clause caps completeness at 3.

Trigger Term Quality

Natural domain phrases a user would say are present: "cross-device portal login", "QR activation", "cancellation", "Caddy". A few natural synonyms are missing (e.g., "QR code login", "second-device approval", "approve login on another device"), matching the good-coverage-with-gaps anchor rather than comprehensive anchor 5.

Distinctiveness Conflict Risk

The description carves a clear niche — optional cross-device login for a Caddy authentication portal — with distinct triggers (QR activation, browser binding, cross-device session) unlikely to fire for unrelated skills. The explicit ownership boundary ("Native login and external provider configuration retain their own owners") further reduces overlap with sibling skills, matching the minimal-conflict anchor 5.