Conciseness

The body is largely lean and operational — tool names, parameters, and rules with no explanation of concepts Claude already knows. A few rhetorical flourishes ('a roster settled late is a roster half the stage never saw', 'leaves the user holding an empty deck') pad slightly beyond the bare rule, which is the 'minor instances that could be trimmed' case, not the every-token-earns-its-place case.

Actionability

Every step is executable instruction, not description: exact tools with parameters (`create_stage` with `folderId`, `set_roster` with persona spec and `providerId::voiceId` binding, `generate_scene` with settled `title`/`type`/`brief`, `read_stage` with `path:/scenes/<order|id>` and `detail:"source"`), plus concrete field checks (`audioId` on speech actions). For an instruction-only skill this covers the common cases fully.

Workflow Clarity

The build sequence is a clearly ordered 5-step list with explicit validation checkpoints: `list_scenes` to verify persistence, `read_stage` to check `audioId` before calling the stage done, and a full feedback loop for failures (retry once with a changed brief, then stop and name the gap). This matches the top anchor — sequence, checkpoints, error recovery, and a done-checklist.

Progressive Disclosure

No bundle files exist, and the body is a well-sectioned, self-contained overview whose only cross-references are to sibling skills (`pro-editing`, topic skills) used as boundary signals rather than nested file refs. At ~95 lines it sits at the upper bound of what belongs inline in one SKILL.md, so structure is good but not the ideal split/overview case.

Specificity

The description lists five concrete, distinct actions: 'how the plan is settled in conversation', 'the order the generation tools are called in', 'how the classroom roster is written', 'when narration has to be re-synthesized', and 'what must be true before a stage is called done' — comprehensive coverage of the build lifecycle. It is not merely naming the domain; each clause names a specific capability.

Completeness

It explicitly answers 'what' ('The baseline method for building ONE stage... Covers [five capabilities]') and 'when' ('Load this before generating or rebuilding any stage from scratch, whatever its subject') with a concrete trigger clause. Both halves are explicit, matching the top anchor.

Trigger Term Quality

Natural trigger phrases are present — 'building ONE stage', 'generating or rebuilding any stage from scratch', 'classroom', 'narration' — which a user of this runtime would plausibly say. A few natural variations are missing (e.g., 'create a lesson', 'new deck', 'pages'), keeping it just below the comprehensive-with-synonyms anchor.

Distinctiveness Conflict Risk

It carves a clear niche ('the baseline method for building ONE stage') and explicitly positions itself against the topic skills ('it is the floor the topic skills build on, not an alternative to them'), minimizing conflict. However, 'whatever its subject' makes it broad enough to co-trigger with those closely related skills, so it is not quite minimal-conflict.