Conciseness

The body is lean: it assumes git competence, skips worktree concept explanations, and lets runnable commands carry the instruction. Minor over-explanation remains — "Why critical: Prevents accidentally committing worktree contents to repository" restates the preceding MUST directive, and the rationalizations table is borderline padding — so it is efficient with minor trim opportunities rather than fully lean.

Actionability

Nearly everything is executable: rev-parse detection commands, a submodule guard, check-ignore verification, `git worktree add`, and a concrete setup matrix. The one gap is `path="$LOCATION/$BRANCH_NAME"`, which references undefined variables, so that block is not copy-paste ready — keeping it at 'mostly executable with minor gaps' rather than fully executable.

Workflow Clarity

The sequence is explicit (Step 0 detect → Step 1a/1b create → Step 2 setup → Step 3 baseline) with validation checkpoints (submodule guard, MUST check-ignore, clean-baseline tests) and error-recovery loops (sandbox fallback, report-failures-and-ask on test failure), plus a quick-reference table mapping every situation to an action. This matches the top anchor: clear sequence, explicit validation, feedback loops for error recovery.

Progressive Disclosure

No bundle files exist, and the body is well-organized with clear section headers, a decision table, and a quick-reference index. At ~165 lines everything is inline; the Quick Reference and Common Rationalizations tables are candidates for a separate reference file, leaving it at 'good structure; most content appropriately placed' rather than a textbook clear-overview-with-references layout.

Specificity

The description names the domain (workspace isolation) and one composite action — "ensures an isolated workspace exists via native tools or git worktree fallback" — but omits the skill's other concrete behaviors (detecting existing isolation, verifying ignore status, baseline testing). It lists 1-2 concrete actions rather than several, matching the anchor for 'names domain and 1-2 concrete actions, but not comprehensive'.

Completeness

It explicitly answers both questions: "Use when starting feature work that needs isolation... or before executing implementation plans" is a concrete when-clause, and "ensures an isolated workspace exists via native tools or git worktree fallback" is a clear what. Both are explicit with concrete trigger phrases, matching the top anchor rather than the 'when could be more explicit' anchor below it.

Trigger Term Quality

Natural trigger phrases are present — "starting feature work", "needs isolation", "before executing implementation plans", "git worktree" — and a user would plausibly say these. A few natural terms are missing, such as "worktree" as a standalone trigger, "parallel branch", or "isolated environment", so it falls just short of comprehensive synonym coverage.

Distinctiveness Conflict Risk

The worktree-isolation niche is mostly distinct with its own triggers, but "before executing implementation plans" overlaps with plan-execution skills and could co-trigger. Minor overlap risk with closely related skills matches this anchor; the clear niche keeps it above the 'could still overlap' level.