diff --git a/src/tools/file-operations.ts b/src/tools/file-operations.ts
index 8f9d484..b0b6c6b 100644
--- a/src/tools/file-operations.ts
+++ b/src/tools/file-operations.ts
@@ -19,6 +19,28 @@ import {
 import { sanitizeParameters } from '../validation/sanitizer.js';
 import { formatParam } from '../utils/cli-helpers.js';
 
+/**
+ * Detect binary content that cannot be meaningfully returned as text.
+ * Checks for null bytes (definitive binary marker) or a high ratio of
+ * non-printable characters (catches ZIP, images, compiled files, etc.).
+ */
+function isBinaryContent(content: string): boolean {
+  if (content.length === 0) return false;
+  // Null bytes are never present in valid UTF-8 text
+  if (content.includes('\0')) return true;
+  // Sample the first 8KB for performance on large files
+  const sample = content.slice(0, 8192);
+  let nonPrintable = 0;
+  for (let i = 0; i < sample.length; i++) {
+    const code = sample.charCodeAt(i);
+    // Allow tab (9), newline (10), carriage return (13), and standard printable range
+    if (code !== 9 && code !== 10 && code !== 13 && (code < 32 || code > 126) && (code < 128)) {
+      nonPrintable++;
+    }
+  }
+  return nonPrintable / sample.length > 0.1;
+}
+
 /**
  * Register all file operation tools
  */
@@ -186,11 +208,25 @@ export async function registerFileOperationTools(server: ObsidianMCPServer): Pro
         const result = await executeObsidianCommand('read', cmdArgs);
         handleCLIResult(result, { operation: 'read_note', identifier: sanitized.file || sanitized.path });
 
+        // Detect binary content — non-text files (ZIP, PDF raw bytes, images, etc.)
+        // will contain null bytes or a high proportion of non-printable characters.
+        const raw = result.stdout;
+        if (isBinaryContent(raw)) {
+          const identifier = sanitized.file || sanitized.path;
+          return {
+            content: [
+              {
+                type: 'text',
+                text: `Cannot read "${identifier}": file appears to be binary (e.g. ZIP, image, compiled file). obsidian_read_note only supports text-based files such as Markdown, plain text, and PDF notes exported as text.`,
+              },
+            ],
+          };
+        }
+
         const offset: number = validated.offset ?? 0;
         const maxChars: number = validated.max_chars ?? 50000;
-        const fullContent = result.stdout;
-        const totalChars = fullContent.length;
-        const chunk = fullContent.slice(offset, offset + maxChars);
+        const totalChars = raw.length;
+        const chunk = raw.slice(offset, offset + maxChars);
         const isTruncated = offset + maxChars < totalChars;
 
         let text = chunk;