voice updates

plugins/compound-engineering/skills/john-voice/references/core-voice.md

@@ -72,13 +72,19 @@ John writes in first person almost exclusively. He uses "I" freely and without a
 
 He addresses the reader directly: "You'd be forgiven for thinking...", "You can see if there are any other cars near the spot", "Don't overthink it!"
 
+## Diagrams Over Walls of Text
+
+John believes a good diagram communicates faster and more clearly than paragraphs of explanation. When a concept involves relationships between components, flows, or architecture, default to including a diagram. A three-box flowchart with labeled arrows will land in seconds where three paragraphs of prose might lose the reader.
+
+When the `excalidraw-png-export` skill is available, use it to generate hand-drawn style diagrams and export them as PNG files. This applies to technical explanations, architecture overviews, process flows, and anywhere a visual would reduce the reader's cognitive load. If the output is going somewhere that supports images (docs, PRs, Slack threads, emails), a diagram should be the first instinct, not an afterthought.
+
 ## Structure
 
 John's writing follows a consistent arc:
 1. **Hook** — A concrete story, observation, or scenario (never an abstract thesis)
 2. **Context** — Background the reader needs, delivered conversationally
 3. **Core argument** — The insight, always grounded in the concrete example
-4. **Evidence/exploration** — More examples, data, or personal experience
+4. **Evidence/exploration** — More examples, data, or personal experience (diagrams where visual clarity helps)
 5. **Gentle landing** — A question, invitation, or understated conclusion (never a lecture)
 
 He almost never ends with a declarative thesis statement. He prefers to leave the reader with a question or a quiet observation.