Conciseness

The body is dense and prescriptive with zero concept re-teaching — every bullet is a repo-specific rule, and it actively budgets itself ("Keep the core-principles section at no more than ten bullets"). Minor trimming is possible: the specification edit gate and sections 6-7 each restate the where-knowledge-belongs philosophy, keeping it just short of the every-token-earns-its-place anchor.

Actionability

For an instruction-only skill the guidance is fully executable: an exact command (`pnpm run valid-layers-check`), exact paths (`browser/menus.ts`, `sessions.*.main.ts`), named contracts (`ISessionsManagementService`, `ISession`/`IChat`), and a 13-row routing table of exact specification paths covering every subsystem. This matches the anchor for concrete, copy-paste-ready guidance covering the common cases.

Workflow Clarity

Sections 1-7 form a coherent sequence (principles → identify area → inspect → implement → validate → record feedback → maintain) with an explicit proportional-validation section and the three-question edit-gate checklist ("If any answer is missing, leave the specification unchanged"). It sits at anchor 4 rather than 5 only because there is no explicit error-recovery loop, e.g. what to do when valid-layers-check fails.

Progressive Disclosure

The skill is a pure router: a well-signaled table maps each area to its specification one level deep, reinforced by "read only the specifications relevant to the change" and heading-scoped searching of the learning inbox. No bundle files exist to fragment content, and the body stays a lean overview — a clear match for the well-signaled one-level-deep-references anchor.

Specificity

The description names a precise domain ("changes to the Agents Window under src/vs/sessions") but lists no concrete actions — "Core principles and workflow router" describes what the skill contains, not what it does. It matches the anchor for naming the domain with minimal or generic actions, and cannot reach 3 because no concrete action is stated.

Completeness

The "when" is explicit and path-scoped ("for changes to the Agents Window under src/vs/sessions"), and a "what" is present ("Core principles and workflow router"), so both halves are answered. It falls short of anchor 5 because the "what" is generic rather than concrete capabilities, while the explicit "when" rules out anchor 3.

Trigger Term Quality

"Agents Window" and "src/vs/sessions" are natural terms a developer would say, but coverage stops there — no subsystem variations the body actually routes to (sessions list, layout, mobile, Copilot Chat, automations). This is some relevant keywords with common variations missing, short of anchor 4's good keyword coverage.

Distinctiveness Conflict Risk

Scoping triggers to a named feature and a specific source path ("Agents Window under src/vs/sessions") gives the skill a clear niche with minimal overlap risk against other skills. This squarely matches the clear-niche anchor.