Conciseness

The ~25-line body is lean: every line states plugin-specific facts (injection events, source globs, env var names and value formats) with zero padding and no explanation of concepts Claude already knows. Matches anchor 5 ('Lean and efficient... every token earns its place'); nothing to trim.

Actionability

Concrete details are present (exact env vars like "CODEX_RULES_MODE=both|static|dynamic|off" and exact file globs like ".omo/rules/**/*.md"), but the body is descriptive rather than instructive — it never shows how to configure a source, disable injection, or what the modes do, and rule "matching" (promised in the description) is never explained. Matches anchor 3 ('Some concrete guidance but incomplete; missing key details'); not 4 because no usage example or semantic explanation accompanies the raw settings list.

Workflow Clarity

As a simple single-purpose reference skill with no multi-step process or destructive operations, the content is organized into clearly labeled fact groups (injection behavior, sources, env knobs, legacy fallback). Scored 4 rather than 5 because the matching/selection behavior is named in the description but absent from the body, leaving one ambiguity about how rules are chosen.

Progressive Disclosure

The skill is under 50 lines with no need for external references, and the content is well organized into labeled lists ("Supported project sources", "Supported environment knobs") with no bundle files to reference. Per the simple-skill guideline this matches anchor 5; not 4 because there is no content that should be split out — everything belongs at this level.

Specificity

The description names the domain ("Codex Rules behavior, injected project rules, supported rule file locations, matching, or environment configuration") but lists no concrete actions or capabilities — it is a topic list, not an action list. It matches anchor 2 ('Names the domain but actions are minimal or generic'), and not 3 because no 1-2 concrete actions (what the skill actually does) are stated; not 1 because the domain is named specifically rather than being entirely vague.

Completeness

The 'when' is explicit ("Use when the user asks about...") but the 'what' is entirely missing — the description never states what the skill does. This matches anchor 2 exactly ('only 'when' is present without 'what'); it is not 3 because there is no clear 'what' at all, and not 1 because a concrete, explicit trigger clause is present.

Trigger Term Quality

Phrases like "injected project rules", "rule file locations", and "environment configuration" are natural things a user would say when needing this skill. It falls just short of anchor 5 because common synonyms and concrete file names users might mention (e.g., CONTEXT.md, .claude/rules, pi-rules) are absent.

Distinctiveness Conflict Risk

"Codex Rules" is a clearly named niche, making it mostly distinct, but generic tail phrases like "matching, or environment configuration" create minor overlap risk with general config or rules-management skills. Not 5 because of that generic overlap; not 3 because the named plugin scope keeps it well above 'somewhat specific'.