Conciseness

The body is dense and table-driven with no filler, but the scripted-vs-exploratory comparison table, the ISTQB definition quote, and parts of the 'Common confusions' table re-explain concepts Claude already knows. These are minor instances of over-explanation that could be trimmed, so this fits anchor 4 rather than 5.

Actionability

As an instruction-only skill it gives concrete, copy-paste-ready guidance: the charter syntax 'Explore <area> With <tools> to discover <information>', 60-90 minute timeboxes, TBS healthy ranges (T 60-80%), a worked charter example, and hard deadlines (PROOF within 30 min, lead review within 24h). Per the rubric's code-vs-instruction note, absence of code is not penalized when guidance is this actionable.

Workflow Clarity

The 'How to use' section gives a clearly sequenced six-step process with an explicit validation checkpoint and error-recovery loop - "if T < 50%, stop and fix the cause (stabilise the environment or narrow the charter), then re-run the session before aggregating" - plus debrief timing rules, matching the top anchor (explicit validation steps and feedback loops), not merely the 'most checkpoints' level below.

Progressive Disclosure

The SKILL.md is a genuine overview that routes to all nine reference files (all verified to exist) via a needs-based routing table ('You need -> Lens -> Reference'), each link annotated with its contents. References are one level deep with only peer cross-links - no nested chains - matching the top anchor for clear overview with well-signaled references.

Specificity

The description lists multiple concrete, domain-specific actions - "Plans and runs time-boxed exploratory testing", "charters (Explore X with Y to discover Z)", "60-90 minute sessions, session sheets with TBS metrics, and the PROOF debrief" - with comprehensive coverage of the skill's capabilities, matching the top anchor rather than the 'minor gaps' level below.

Completeness

Both questions are answered explicitly: the 'what' (SBTM cycle: charters, sessions, session sheets with TBS metrics, PROOF debrief) and a concrete 'when' ("Use when deciding what to explore with the time available, and how to run and record those sessions" plus the scarcity scenarios). The 'when' is explicit and specific, so this fits the top anchor, not the score-4 level where 'when' could be more explicit.

Trigger Term Quality

Natural trigger phrases like "tester hours are scarce before a release", "code freeze", "year-end payroll", and "device and environment the scripted suite never touches" are present, but common synonyms such as 'ad-hoc testing' or 'unscripted testing' are absent, leaving a few natural terms missing.

Distinctiveness Conflict Risk

A clear niche (whole SBTM cycle) with explicit disambiguation from the closest sibling - "Broader than exploratory-charter-author, which writes one charter document: this owns the whole cycle" - giving minimal conflict risk.