Conciseness

The body is dense, imperative, and free of explanations of concepts Claude already knows ('Never run implementation discovery's mutation steps', 'A checked box is planned progress, not proof that tests passed'). Minor trim opportunities remain: reference resolution is stated twice ('Resolve this reference beside the installed entrypoint' in section 1 and 'resolve this trusted installed helper beside this entrypoint' in section 3) and the precedence paragraph in the skill-context section is boilerplate-heavy.

Actionability

Concrete guidance throughout: exact invocation 'Run `python3 -I -B <helper>` with JSON on stdin', a complete JSON input example, exact config keys with defaults ('.ai-factory/PLAN.md', '.ai-factory/plans/', ...), and exact continuation commands ('/aif-implement @<entrypoint>', '/aif-verify'). It falls short of fully copy-paste-ready because section extraction names techniques ('Batch section extraction when practical (fixed `awk`, or heading searches + bounded Read ranges)') without a literal command, and the manual-tree fallback has no worked example.

Workflow Clarity

Clear numbered sequence (resolve context -> read just enough -> present summary and file map) with prerequisite reading order and explicit validation checkpoints ('Validate the ultra marker and the existence/containment of Phase Index links first'). Error recovery and stop conditions are explicit at nearly every step ('If sections are absent, say which phase lacks a file/objective summary'; 'If Python/helper execution is unavailable or not permitted, draw the same tree manually'; 'a missing reference stops discovery'). The skill is read-only, so the destructive/batch validation cap does not apply.

Progressive Disclosure

The body is an overview that cleanly offloads detail to two well-signaled, one-level-deep references that both exist on disk: [read-only discovery](references/PLAN-OVERVIEW-DISCOVERY.md) and [file_tree.py](references/plan-overview/file_tree.py). PLAN-OVERVIEW-DISCOVERY.md contains no further nested bundle references, navigation is easy, and content is appropriately split.

Specificity

Concrete actions are explicit: 'Summarize an existing fast/full/ultra/fix plan', 'show its planned file changes', 'without implementing or editing it', with the domain enumerated across all four plan modes and an explicit non-goal. It sits above anchor 3's generic partial coverage but below anchor 5, which expects multiple distinct actions rather than two.

Completeness

Both questions are explicitly answered: what ('Summarize an existing fast/full/ultra/fix plan and show its planned file changes without implementing or editing it') and when ('Use for a plan overview, file map, or a quick explanation before implementation') with concrete trigger phrases. The 'when' clause is explicit and specific, not merely implied, so anchor 4's caveat does not apply.

Trigger Term Quality

Natural phrases a user would say are present: 'Use for a plan overview, file map, or a quick explanation before implementation', plus 'summarize' and 'planned file changes'. A few natural variations are missing (e.g., 'explain this plan', 'what will this plan change'), so it does not reach comprehensive synonym coverage.

Distinctiveness Conflict Risk

The clause 'without implementing or editing it' plus the overview/file-map framing carves a clear niche distinct from implementation or fix skills. Minor overlap risk remains with sibling plan-management skills that share the 'plan' keyword family, preventing a minimal-conflict score of 5.