Conciseness

The ~46-line body is lean and fully operational: "Render when the discussion has >=3 moving parts", "2–5 blocks per canvas", "One diagram, one point. If a diagram needs a paragraph, redraw the diagram." No concept explanations or padding — every token earns its place. Not below 5 because nothing can be trimmed without losing instruction.

Actionability

For an instruction-only skill the guidance is fully concrete: exact output path pattern ("`<tmpdir>/visual-thinking-<timestamp>.html` (`%TEMP%` on Windows, `$TMPDIR` or `/tmp` elsewhere)"), open commands ("`start` / `open` / `xdg-open`"), and a seven-type block taxonomy with one-line selection guidance. The deferred details live in real bundle files (references/diagrams.md, assets/canvas-template.html). Anchor 5; the absence of code is not penalized because the guidance is directly executable.

Workflow Clarity

A clear four-step sequence (Extract → Compose → Render → Feed back) with a go/no-go gate (rule 1: ">=3 moving parts"), an explicit failure check ("If the canvas restates everything already said in chat, it failed") and a regeneration rule ("never edit diagrams in place"). Scored 4 rather than 5 because there is no explicit validation/retry checkpoint on the rendered output itself (e.g. verifying the file opened or Mermaid rendered) — a minor gap, though the operation is low-risk (temp file, nothing in the repo).

Progressive Disclosure

The body is a clear, well-organized overview that splits detail correctly: the diagram/HTML contract in [references/diagrams.md] and the shell in [assets/canvas-template.html], both clearly signaled one-level-deep links, and both files exist with real content. Easy navigation, no inlining of content that belongs in separate files.

Specificity

"Turn an idea, change or decision into a visual HTML canvas with Mermaid diagrams" names the domain and one composite action, but lists only 1-2 concrete actions; capabilities like diagram variety or export live only in the body. It fits anchor 3, not 4, because it does not list several specific actions.

Completeness

Both "what" ("Turn an idea, change or decision into a visual HTML canvas with Mermaid diagrams") and "when" (explicit "Trigger:" clause) are present. Scored 4 rather than 5 because the when-guidance is bare trigger keywords and lacks the situational criterion (">=3 moving parts") that only appears in the body, so it could be more explicit.

Trigger Term Quality

"Trigger: visualizá esto, canvas" includes one genuinely natural phrase (Spanish "visualizá esto") plus the generic keyword "canvas", but misses common variations and synonyms (English "visualize this", "diagram", "map this out", "draw"). Anchor 3 fits — relevant keywords present, common variants missing; not 2 because a real natural trigger phrase exists.

Distinctiveness Conflict Risk

"visual HTML canvas with Mermaid diagrams" carves a clear niche, but the bare trigger term "canvas" carries minor overlap risk with generic HTML-canvas or diagramming/dataviz skills. Mostly distinct with minor overlap — anchor 4.