Conciseness

Lean and domain-focused — the Rule, Hard Rule, and code blocks carry the load with no generic padding about what React Router or SPAs are; the brief "Why" and mechanistic note ("React sees a different component at the outlet position... and unmounts the entire subtree") earn their place as non-obvious domain knowledge. Not a 2 because there is no unnecessary explanation of concepts Claude already knows.

Actionability

Gives concrete, executable guidance: the `app/root.tsx` AppLayout-around-Outlet snippet, an explicit file-tree naming convention for pathless routes (`_app.tsx`, `_app.<segment>.tsx`, bare `<segment>.tsx`), and a labeled anti-pattern — copy-paste ready and specific. Not a 2 because the examples are real code and concrete file names rather than pseudocode.

Workflow Clarity

The "Adding a New Route" section gives unambiguous decision guidance mapped to each pattern (Pattern #1 → render page content only; Pattern #2 → `_app.<segment>.tsx` vs bare `<segment>.tsx`), and the task is a single decision rather than a multi-step destructive operation, so validation checkpoints are not applicable. Not a 2 because the single action is clearly sequenced by pattern with no ambiguity.

Progressive Disclosure

Self-contained with well-organized sections (Rule, Why, Hard Rule, Two Correct Patterns, Anti-Pattern, Chat-First Routes, Adding a New Route, Related Skills) and no need for external bundle files; cross-skill navigation is signaled via Related Skills. No bundle files exist in references/scripts/assets, and the body has no nested or dangling references.

Specificity

Lists multiple concrete actions — "add routes without remounting the app shell", "adding a new route", "fixing agent sidebar reloads on navigation", "choosing between `root.tsx` layout and pathless `_app.tsx` layout patterns" — matching the anchor for listing several specific concrete actions.

Completeness

Explicitly answers both what ("How to add routes without remounting the app shell") and when ("Use when adding a new route, fixing agent sidebar reloads on navigation, or choosing between...") with an explicit Use-when clause, matching the top anchor.

Trigger Term Quality

Includes natural triggers like "adding a new route" and "sidebar reloads on navigation", but "choosing between `root.tsx` layout and pathless `_app.tsx` layout patterns" is technical jargon a user would rarely say verbatim, so common-variation coverage is incomplete. Not a 3 because the jargon-heavy third trigger lacks natural phrasing; not a 1 because several terms are genuinely user-sayable.

Distinctiveness Conflict Risk

Highly specific to client-side routing and app-shell remount behavior, with distinct triggers unlikely to fire for unrelated skills, matching the clear-niche anchor.