Conciseness

In roughly 370 words the body delivers seven formulas with working thresholds ("At 50% margin you break even at 2.0x; at 25% margin, 4.0x"), data-sourcing rules, reconciliation guidance, and decision routing — every token earns its place and nothing explains concepts Claude already knows. It is not anchor 4 because the few rhetorical lines ("the numbers that decide whether a campaign lives") are single-line emphasis, not over-explanation that could be trimmed.

Actionability

Guidance is fully concrete for an instruction-only skill: exact tool names ("pull_google_ads_performance", "list_connected_accounts"), complete formulas for every metric, a healthy LTV:CPA line ("Roughly 3:1 or higher"), and named hand-off skills (**attribution**, **optimize**, **kill-scale-rules**, **mmm-budget-planner**). A model can execute each step without guessing, matching the fully-executable anchor.

Workflow Clarity

The sequence — confirm account, pull real figures, compute blended and per-platform, reconcile attribution, report inputs and derived numbers, then route the decision — is clear and includes real checkpoints ("ask rather than assume", "Reconcile with the attribution skill before trusting a single platform's ROAS"). It falls short of anchor 5 because the order is implied by section arrangement rather than an explicit step sequence, and there are no error-recovery feedback loops.

Progressive Disclosure

The body is under 50 lines with no bundle files (references/, scripts/, assets/ are absent) and no need for external references, yet is organized into tight, well-labeled sections (core numbers, how to use it, report, rules). Per the simple-skill guideline this matches the well-organized-sections case for a top score.

Specificity

"Calculate ROAS, CPA, break-even, max CPC, and campaign profitability from real spend and revenue, and set realistic targets" names five-plus concrete calculations plus an outcome action, matching the comprehensive-coverage anchor. It clearly exceeds anchor 4 ('several specific actions; minor gaps') since every capability in the niche is enumerated.

Completeness

The 'what' is explicit ("Calculate ROAS, CPA, break-even, max CPC, and campaign profitability... and set realistic targets") and the 'when' is an explicit "Use when" clause enumerating concrete trigger questions. Both are present with concrete triggers, matching anchor 5 rather than anchor 4 where the 'when' could be more specific.

Trigger Term Quality

Phrases like "whether a campaign is profitable", "what ROAS or CPA they need", "what to bid", and "unit economics behind ad spend" are natural user phrasings. It falls short of anchor 5 because spelled-out synonyms such as "return on ad spend" or "cost per acquisition" are absent, leaving a few natural term variations missing.

Distinctiveness Conflict Risk

"ROAS", "CPA", "break-even", "max CPC", and "unit economics behind ad spend" carve out a clear ad-profitability-math niche with distinct triggers and minimal conflict risk against generic marketing or optimization skills. It is not anchor 4 because no meaningful overlap with a closely related skill's triggers is evident.