Conciseness

The ~15-line body is lean and assumes competence: a routing table, the gating condition ("Refuses to run unless `gh stack` is installed and `gh stack view --json` exits 0"), and a pointer to scope rules. It explains nothing Claude already knows and every sentence carries new, load-bearing information. Fits the 'lean and efficient; every token earns its place' anchor exactly.

Actionability

The body's instructions are "Read `skills/controller.md` and follow it" plus a command table mapping to `commands/*.md` — but none of those files exist in the bundle (only `scripts/` with 8 shell scripts exists, none referenced from the body). The one executable check written out (`gh stack view --json` exits 0) is concrete, but the specific steps for every phase live in files that are missing, so executing this skill as written fails immediately. This matches 'minimal concrete guidance; high-level hints but missing the specific steps to execute' better than the level-3 anchor, since the missing files are the guidance itself rather than a detail gap.

Workflow Clarity

The four phases (start, continue, validate, push) are sequenced in the table and a gating preflight is stated, which is a real sequence. But the actual checkpoints and recovery loops are delegated to files that don't exist, so as written the validation checkpoints are implicit rather than explicit — matching 'steps listed but validation gaps; checkpoints missing or implicit'. This is also a batch/destructive workflow (rebase + push of every branch), and the body itself contains no validate→fix→retry loop, which caps it at 3.

Progressive Disclosure

Scored against the actual bundle: every referenced path is broken — `skills/controller.md`, `commands/start.md`, `commands/continue.md`, `commands/validate.md`, `commands/push.md`, and `guidelines.md` do not exist anywhere in the bundle, while the 8 real files in `scripts/` (preflight, stack-status, validate-branches, push-guard, snapshot, etc.) are never referenced from the body. The one-level routing idea is right and the table is well-signaled, but navigation leads nowhere and the existing bundle content is undiscoverable, which fits the level-2 anchor (references buried/unusable) rather than the level-3 'references present but not clearly signaled'.

Specificity

The description lists multiple concrete actions — "Rebases a gh-stack-tracked chain of stacked branches onto its updated base, guides conflict resolution, validates the stack, and pushes every branch with fork-aware PR creation" — covering the full workflow comprehensively with no vague filler. It matches the anchor for multiple specific concrete actions with comprehensive coverage; nothing is generic or abstract, so the level-4 anchor ('minor gaps in coverage') is too low.

Completeness

What is answered concretely (rebase the stack, resolve conflicts, validate, push, open PRs) and when is answered with equivalent explicit trigger guidance: "Activated by commands: /start, /continue, /validate, /push" plus prerequisites ("Requires the gh-stack extension and an existing tracked multi-branch stack; refuses to run otherwise") and an explicit negative trigger ("Do NOT use it to rebase a single branch onto main"). This is not the level-4 case of a weakly implied 'when' — the trigger guidance is explicit, concrete, and even states when not to use it.

Trigger Term Quality

Natural terms a user of this tool would say are present: "rebase", "stacked branches", "stack", "conflict resolution", "pushes", "PR creation". A few natural variations are missing (e.g. "stacked PRs", "update my branches", "gh stack" as a user phrase), so it fits the 'good keyword coverage; a few natural terms missing' anchor rather than the comprehensive-synonyms anchor at 5.

Distinctiveness Conflict Risk

It carves out a clear niche (gh-stack-tracked multi-branch stacks) and actively de-conflicts with the nearest overlapping capability: "Do NOT use it to rebase a single branch onto main — plain git rebase does that", plus a hard refusal condition. Minimal conflict risk with any other skill; the level-4 anchor ('minor overlap risk') understates the explicit negative scoping.