Conciseness

The same four bugs are covered three times: the "four cardinal mistakes" ("Target too high", "Wrong SLI", "No error budget policy", "Single-window burn-rate alert") reappear as slo_review.py checks ("target_too_high", "cpu_as_sli", "no_error_budget_policy") and again in the Anti-patterns section ("99.99% on every endpoint", "CPU usage as SLI", "No error budget policy", "Single-window burn-rate alert"). The SLI/SLO/SLA definition block and the 99.9% error-budget arithmetic also re-teach SRE Workbook canon Claude already knows. Mostly efficient, but the duplication and known-concept explanation mean it is more than 'minor instances of over-explanation' (level 4).

Actionability

Concrete, copy-paste-ready commands with real flags ("python scripts/slo_designer.py --service checkout-svc --sli-type request-success-rate --target 99.9 --window-days 30 --owner team-checkout"), enumerated SLI formulas, a deterministic target rule ("target = floor(p50 of last 30 days × 100) / 100"), and named checks with thresholds ("target ≥ 99.99%", "window < 7 days"). Falls short of level 5 because every invoked script (slo_designer.py, error_budget_calculator.py, slo_review.py) is referenced but absent from the bundle, so the commands are not actually executable as shipped.

Workflow Clarity

Workflow 1 is a clear 9-step sequence with an explicit validation gate ("Run slo_review.py — must pass before the SLO is 'live'") and a refusal gate upstream (slo_designer "Refuses to render if any required field is missing (exit 1)"); Workflow 2 includes fix loops ("fix any FAIL findings", "Adjust thresholds"). Not level 5 because the recovery loop when review fails in Workflow 1 is only implied, and Workflow 3 describes a pipeline without any checkpoint.

Progressive Disclosure

The in-document structure is good and the References section clearly signals one-level-deep files ("references/slo_principles.md — SLI vs SLO vs SLA, Google SRE Workbook canon"), but none of the nine referenced bundle files exist: references/ (4 files), scripts/ (3 files), and assets/ (2 files) are all absent from the bundle. Every "See references/sli_design.md for examples and anti-patterns" pointer and every script invocation dangles, so the navigation structure cannot actually be followed. Structure is better than level 2 (references are not buried and content is well sectioned), but the broken bundle is more than the 'minor organization gaps' of level 4.

Specificity

The description lists multiple concrete capabilities with named tools and outcomes: "Ships SLO designer, error-budget calculator with multi-window burn-rate thresholds, and SLO reviewer that catches the common bugs (target too aggressive, window too short, conflicting SLOs, no SLI definition)". This matches the anchor 'lists multiple specific concrete actions; comprehensive coverage'; it is not level 4 because there are no meaningful coverage gaps in the action inventory.

Completeness

Both what and when are explicit: "Use when defining, reviewing, or operating SLOs/SLIs/error budgets" followed by concrete trigger phrases, and a clear statement of what the skill ships. Matches the anchor 'clearly and explicitly answers both what AND when with concrete trigger phrases'; level 4 would require the 'when' to be less explicit, which it is not.

Trigger Term Quality

Triggers include natural user phrasings and synonyms: "define an SLO", "what should our SLO be", "error budget", "burn rate", "SLI", "service level objective", "multi-window burn-rate alert", plus a catch-all "any reliability-target question". Comprehensive natural-term coverage including synonyms (SLI / service level objective); nothing common is missing.

Distinctiveness Conflict Risk

It carves out a clear niche and actively disambiguates: "NOT a generic observability skill — specifically the SLO discipline", with triggers anchored to SLO-specific vocabulary (error budget, burn rate, SLI). Minimal conflict risk with general observability or incident-response skills; matches 'clear niche with distinct triggers'.