diff --git a/src/resources/extensions/sf/markdown-renderer.js b/src/resources/extensions/sf/markdown-renderer.js
index a0e3cae7d..9297d957b 100644
--- a/src/resources/extensions/sf/markdown-renderer.js
+++ b/src/resources/extensions/sf/markdown-renderer.js
@@ -587,7 +587,14 @@ function renderSlicePlanMarkdown(slice, tasks, gates = []) {
 		}
 	}
 	lines.push("");
-	return `${lines.join("\n").trimEnd()}\n`;
+	// Collapse 3+ consecutive newlines down to 2. Task descriptions sometimes
+	// contain double blanks (model-emitted multi-paragraph content + paragraph
+	// padding) that survive normalizeMarkdownBlockSpacing's heading-only logic.
+	// Without this, the rendered S0?-PLAN.md trips MD012/no-multiple-blanks in
+	// pre-execution checks and blocks the autonomous loop at execute-task.
+	// auto_fix_check_failures was supposed to handle this but doesn't run for
+	// .sf/milestones/ files — quicker to emit clean markdown at the source.
+	return `${lines.join("\n").trimEnd()}\n`.replace(/\n{3,}/g, "\n\n");
 }
 export async function renderPlanFromDb(basePath, milestoneId, sliceId) {
 	const slice = getSlice(milestoneId, sliceId);