diff --git a/src/knowledge.rs b/src/knowledge.rs
index 3baa900..05c50a0 100644
--- a/src/knowledge.rs
+++ b/src/knowledge.rs
@@ -720,7 +720,9 @@ async fn synthesize_merge<D: KnowledgeDao + 'static>(
         entities refer to the same real-world thing and are about to be merged. Write a \
         single neutral third-person description (1-2 sentences, max 300 chars) that \
         preserves any concrete facts in either source. Do not invent details. Do not \
-        editorialize. Return ONLY the merged description — no preamble, no quotes.";
+        editorialize. Plain prose only — no markdown, no bold, no italics, no headings, \
+        no bullets, no lists, no code fences. Return ONLY the merged description — no \
+        preamble, no labels, no quotes.";
     let prompt = format!(
         "Entity A: {} [{}]\nDescription: {}\n\nEntity B: {} [{}]\nDescription: {}\n\nMerged description:",
         source.name, source.entity_type, source_desc,
@@ -731,15 +733,46 @@ async fn synthesize_merge<D: KnowledgeDao + 'static>(
     let model_used = ollama.primary_model.clone();
     let proposed = match ollama.generate(&prompt, Some(system)).await {
         Ok(out) => {
-            // Some models open with their own framing — strip a
-            // leading quote or "Merged:" lead-in defensively.
-            let cleaned = out
-                .trim()
+            // Strip the framing models reach for even with explicit
+            // "no preamble" guidance: leading "Merged description:"
+            // labels, wrapping quotes, ``` code fences, leading
+            // bullets / hash headings. Belt-and-braces against the
+            // system prompt's plain-text directive.
+            let mut s = out.trim().to_string();
+            s = s
                 .trim_start_matches("Merged description:")
+                .trim_start_matches("Merged Description:")
                 .trim()
+                .to_string();
+            // Code fences (``` or ```text)
+            s = s
+                .trim_start_matches("```text")
+                .trim_start_matches("```markdown")
+                .trim_start_matches("```")
+                .trim_end_matches("```")
+                .trim()
+                .to_string();
+            // Markdown headings / bullets at the very start
+            while let Some(stripped) = s
+                .strip_prefix('#')
+                .or_else(|| s.strip_prefix('*'))
+                .or_else(|| s.strip_prefix('-'))
+                .or_else(|| s.strip_prefix('>'))
+            {
+                s = stripped.trim_start().to_string();
+            }
+            // Wrapping quotes
+            s = s
                 .trim_matches(|c| c == '"' || c == '\'')
                 .to_string();
-            cleaned
+            // Inline emphasis: drop standalone `**` / `*` / `__` /
+            // `_` markers without trying to parse markdown — just
+            // remove the punctuation. Rare enough that this naive
+            // replace is fine.
+            s = s
+                .replace("**", "")
+                .replace("__", "");
+            s
         }
         Err(e) => {
             log::warn!("synthesize_merge generate failed: {:?}", e);