Conciseness

Lean and dense with project-specific invariants Claude cannot know (ghostHash seeding rules, pathZForRow/pathXForCol contracts, override semantics, world[][] as single source of truth); it assumes competence, teaches no general concepts, and every section carries non-obvious constraints. Not 4 because no section contains over-explanation that could be trimmed — even the rationale lines (e.g. why the reveal cache would lie on nondeterminism) encode project-critical consequences.

Actionability

Concrete, executable-by-name guidance throughout: exact function signatures and responsibilities (ghostCellAt, getGhostNeighbors, applyToolToCell), the exact cell schema "{ terrain, kind, floors, buildingType, fenceSide, extras }", and precise density formulas like "(h % 100) < 30 → -1". Per the code-vs-instruction note the absence of code is not penalized, but it stops short of 5 because there are no copy-paste-ready snippets or worked examples for the common change cases.

Workflow Clarity

The doc is a constraint contract rather than a step sequence, but it closes with an explicit, checkable Validation section (pan east for continuous strips, pan away and back for identical regen, bridge rendering, home-board isolation) that serves as verification checkpoints. Not 5 because there is no sequenced workflow for making a change (which helpers to touch first, order of operations) and no fix-and-retry feedback loop around the validation checks; not 3 because validation is explicit and concrete, not merely implied.

Progressive Disclosure

A single self-contained file with well-organized, clearly headed sections covering one coherent subsystem; no bundle files exist and none are needed at this size, so per the simple-skill guidance well-organized sections alone merit full credit. Navigation is easy — sections are scannable and the 'Don't' and 'Validation' sections are prominently separated.

Specificity

Names several concrete areas — "ghost board generation, path / road / river continuity, deterministic regen, edge connections" — plus the precise anchor "anything that runs inside makeGhostWorld in tiny-world-builder.html". Falls short of 5 because it lists topics/trigger surfaces rather than the concrete actions the skill performs, and 'anything that runs inside...' is a catch-all; above 3 because coverage of the domain is broad and specific, not just 1-2 items.

Completeness

The 'when' is explicit and rich ("Use when changing ghost board generation, ... or anything that runs inside makeGhostWorld"), but the 'what' — what the skill actually does or contains — is never stated, only weakly implied by the topic list. Not 2 because the detailed when-clause doubles as a partial statement of subject matter, going beyond a bare "Use when working with documents"; not 4 because no explicit capability statement exists, and per the guidelines only what is explicitly stated counts.

Trigger Term Quality

Comprehensive natural-term coverage for this codebase niche: "path / road / river continuity", "deterministic regen", "edge connections", plus the exact identifiers a user or Claude would mention ("makeGhostWorld", "tiny-world-builder.html") and synonyms (path/road, regen/regeneration). Not 4 because no common variation users would say when touching this code is missing.

Distinctiveness Conflict Risk

Clear niche with distinct triggers: a single named function in a single named file ("makeGhostWorld in tiny-world-builder.html") plus unique domain terms like ghost boards and edge connections. Minimal conflict risk with any other skill; nothing generic remains.