Conciseness

The body is lean and system-specific throughout: "One versioned volume per user. Every write is a new version; deletes keep history." states the core model in two sentences, tables carry all operational detail, and no concept Claude already knows (filesystems, syncing, conflict resolution generally) is re-explained. I looked for trimmable over-explanation and found none — every line states a path, rule, tool, or failure mode unique to this system — so it matches the anchor-5 "every token earns its place" rather than the anchor-4 "minor instances of over-explanation".

Actionability

Guidance is fully concrete: copy-paste checks ("mountpoint -q /volume", "ls ~/\"Cua Volume\""), exact paths ("agents/<you>/outputs/", "public/", "spaces/<this space>/"), exact tool names with their uses, exact state values ("pending_upload", "conflict", "feed is live/off/offline", "last_error"), the concrete conflict naming pattern "name (conflict from <device> <date>).ext", and the specific refusal code "secret_detected". Per the rubric's instruction-only note, absence of code is not penalized when the guidance is this actionable; it covers the common cases (verify mount, place outputs, handle conflicts, avoid secrets) matching anchor 5.

Workflow Clarity

Explicit checkpoints are present (verify the mount and the CUA-VOLUME-UNAVAILABLE.txt sentinel before trusting /volume; "check volume_sync_status" before relying on a file; "Close files before telling the user they are ready") and every failure mode has an error-recovery loop (refused write → ask, secret_detected → remove the secret, conflict → tell the user or merge, offline → "say so rather than trust a stale file"). It sits at anchor 4 rather than 5 because the main save-and-share sequence (write to outputs/, close, verify upload, tell the user the path) must be assembled from three separate sections rather than stated as one ordered workflow with an explicit final verification of upload completion. The destructive-operation cap does not apply: deletes keep history and are restorable via volume_restore, so no unrecoverable batch operation lacks validation.

Progressive Disclosure

The single file is well organized with clear sections ("Where it is", "Layout and what you may do", "Tools", "Sync and conflicts", "Never put secrets in the volume") and needs no external references. The rubric's simple-skill exception (well-organized sections alone score 5) applies to skills under 50 lines; this body is ~70 lines, slightly over that compact threshold, with the tools table and sync detail being the natural split point if the skill grows. That places it at anchor 4 — good structure, content appropriately placed for its size — rather than 5; it is clearly above anchor 3, which requires content that should be separate inlined or buried references.

Specificity

Concrete capabilities are stated — "mounted as a folder (/volume on Linux, ~/Cua Volume on macOS), so any program reads and writes it directly" plus specific uses ("your memory and outputs in your agent home", "shared reference in public/", "hand files to the user or to other agents"). It falls short of anchor 5 because capability coverage has gaps: versioning, sync, history, and restore are never mentioned; it is clearly above anchor 3, which expects only 1-2 concrete actions.

Completeness

Both halves are explicit: what ("the one volume every Space and agent of this user shares... Use it for anything that must outlive this Space") and when ("Use when the user mentions the volume, Cua Volume, shared files, your home or memory, or saving results"). This mirrors the anchor-5 example pattern exactly — clear what plus an explicit 'Use when' clause with concrete trigger phrases; nothing is left to inference.

Trigger Term Quality

The explicit trigger list "the volume, Cua Volume, shared files, your home or memory, or saving results" covers the natural phrases a user in this environment would say, matching the "good keyword coverage; a few natural terms missing" anchor. Not 5: common variations like "sync", "persist", or "share with other agents" are absent; not 3: the terms present go well beyond a single generic keyword.

Distinctiveness Conflict Risk

"Cua Volume" names a distinct product niche with dedicated triggers, so it is mostly distinct; however "saving results" and "your home or memory" are broad enough to fire for memory or generic output-saving skills — minor overlap risk with closely related skills, matching anchor 4. Not 5 due to those broad triggers; not 3 since the core volume/Cua Volume triggers are unambiguous.