Conciseness

Nearly every line carries non-obvious operational fact (proxy routing, public-URL requirement, multiples-of-16 sizing, host-swapping queue URLs) rather than concepts Claude already knows. Not level 5 because the proxy/credentials story is restated in four places — Inputs ("bills the Ads agent"), "Credentials at run time", Workflow step 1, and the Failure Modes 401 row — and "The proxy does not upload local files" appears three times; consolidating would trim tokens without losing anything.

Actionability

Fully executable: three copy-paste bash invocations with real flags and values ("--ref-image \"https://.../anchor.png\"", "--image-size 1728x2304"), a Failure Modes table mapping exact symptoms to exact fixes ("Drop concurrency to 2-3"), and concrete prompt advice ("natural skin texture with pores, slight asymmetry"). Common cases are covered; the only shortcut is ".../generate.py" in two examples, which is unambiguous given the first example spells out the full path.

Workflow Clarity

The user workflow is unambiguous (run the command with the right flags), the script's behavior is laid out as a clear 6-step sequence, and validation is explicit in Quality Checks: "Output file exists and is > 1 KB", "confirm the output dimensions match the requested WIDTHxHEIGHT", and a Failure Modes table that provides error→fix feedback loops. Not level 4 because checkpoints are explicit and recovery paths are given, not implied.

Progressive Disclosure

Well-organized sections with one-level-deep, real references: the bundle's scripts are correctly cited and characterized (media_proxy.py as the active helper, fal_helpers.py as "LEGACY... kept for reference only" — verified against the actual files), plus external model pages and a signaled pointer to sibling skills ("Safe zones: see create-image-fal"). Not level 5 because ~127 lines of mixed operational detail (Model notes, Cross-provider parity note, storyboard-consumer pointers) all live inline in SKILL.md where some could be split into a reference file for easier navigation.

Specificity

The description lists multiple concrete actions and capabilities: "Generate a single photoreal or designed image", "Routes to text-to-image or the edit variant depending on whether a reference image is provided", plus concrete model specifics ("fixed sizes", "custom output sizes up to 3840px"). Coverage is comprehensive for a single-purpose generation skill; not level 4 because there are no meaningful gaps — even routing behavior and model-family differences are stated explicitly.

Completeness

The "what" is explicit ("Generate a single photoreal or designed image with OpenAI gpt-image via fal.ai" with model families and routing) and the "when" is an explicit trigger clause: "Use for photoreal character anchors, scene keyframes, and designed sheets (e.g. storyboards) where precise layout and legible text matter." Both are concrete, matching the level-5 anchor exactly; level 4 would require a vaguer 'when'.

Trigger Term Quality

Good natural-term coverage: "photoreal", "image", "character anchors", "scene keyframes", "storyboards", "designed sheets", "gpt-image", "fal.ai" — terms a user in this video/ads pipeline would naturally say. Not level 5 because a few common variations are missing (e.g. "image generation", "PNG", "keyframe image", "edit an image with a reference").

Distinctiveness Conflict Risk

Clear niche: gpt-image generation via fal.ai, explicitly positioned against the sibling Higgsfield path ("the FAL fallback for Higgsfield's gpt_image_2"), with distinct triggers (character anchors, scene keyframes, storyboard sheets). Overlap risk with other image skills is minimal because the model, provider, and use-cases are all pinned; not level 4 since it doesn't merely reduce overlap — it names the exact differentiators.