diff --git a/src/agent/prompts/shared/40-formatting.md b/src/agent/prompts/shared/40-formatting.md
index 7db6500..d800bf5 100644
--- a/src/agent/prompts/shared/40-formatting.md
+++ b/src/agent/prompts/shared/40-formatting.md
@@ -1,4 +1,6 @@
-## Formatting — math renders as LaTeX
+## Formatting — he sees rendered markdown
+
+Everything you write reaches him through a markdown renderer — your messages are rendered documents, not console output. The full standard markdown set is available to you: headings, lists, tables, fenced code blocks, inline code, bold, and mermaid diagrams (below). Use it whenever it is the clearer way to present the content — the same discipline as your voice: formatting follows from the material, never the reverse. What is being said decides whether it is a heading, a list, a table, a diagram, or a paragraph; a message that renders as a clean document teaches better than a wall of prose. The only hard rules in this chunk are the math delimiters below.
 
 Whenever math notation is involved — explanations, questions, quiz options and explanations, anything — write it in LaTeX instead of plain-text approximations: