diff --git a/src/cloudcode/count-tokens.js b/src/cloudcode/count-tokens.js
index c1088b9..be12a70 100644
--- a/src/cloudcode/count-tokens.js
+++ b/src/cloudcode/count-tokens.js
@@ -3,8 +3,8 @@
  *
  * Implements Anthropic's /v1/messages/count_tokens endpoint
  * Uses official tokenizers for each model family:
- * - Claude: @anthropic-ai/tokenizer (99.99% accuracy)
- * - Gemini: @lenml/tokenizer-gemini (99.99% accuracy)
+ * - Claude: @anthropic-ai/tokenizer
+ * - Gemini: @lenml/tokenizer-gemini
  *
  * @see https://platform.claude.com/docs/en/api/messages-count-tokens
  */
@@ -112,6 +112,12 @@ function estimateTextTokens(text, model, geminiTok = null) {
 /**
  * Extract text from message content
  *
+ * Note: This function only extracts text from 'text' type blocks.
+ * Image blocks (type: 'image') and document blocks (type: 'document') are not tokenized
+ * and will not contribute to the token count. This is intentional as binary content
+ * requires different handling and Anthropic's actual token counting for images uses
+ * a fixed estimate (~1600 tokens per image) that depends on image dimensions.
+ *
  * @param {string|Array} content - Message content
  * @returns {string} Concatenated text
  */
@@ -194,7 +200,7 @@ function countTokensLocally(request, geminiTok = null) {
 /**
  * Count tokens in a message request
  * Implements Anthropic's /v1/messages/count_tokens endpoint
- * Uses local tokenization for all content types (99.99% accuracy)
+ * Uses local tokenization for all content types
  *
  * @param {Object} anthropicRequest - Anthropic format request with messages, model, system, tools
  * @param {Object} accountManager - Account manager instance (unused, kept for API compatibility)
diff --git a/src/server.js b/src/server.js
index 40c41d8..86c92a2 100644
--- a/src/server.js
+++ b/src/server.js
@@ -599,7 +599,7 @@ app.get('/v1/models', async (req, res) => {
 
 /**
  * Count tokens endpoint - Anthropic Messages API compatible
- * Uses hybrid approach: local tokenizer for text, API for complex content (images, documents)
+ * Uses local tokenization with official tokenizers (@anthropic-ai/tokenizer for Claude, @lenml/tokenizer-gemini for Gemini)
  */
 app.post('/v1/messages/count_tokens', async (req, res) => {
     try {
diff --git a/tests/test-count-tokens.cjs b/tests/test-count-tokens.cjs
index 71be240..325a72d 100644
--- a/tests/test-count-tokens.cjs
+++ b/tests/test-count-tokens.cjs
@@ -2,7 +2,7 @@
  * Test Count Tokens - Tests for the /v1/messages/count_tokens endpoint
  *
  * Verifies token counting functionality:
- * - Local estimation using gpt-tokenizer
+ * - Local estimation using official tokenizers (@anthropic-ai/tokenizer for Claude, @lenml/tokenizer-gemini for Gemini)
  * - Request validation
  * - Different content types (text, tools, system prompts)
  */
@@ -436,6 +436,47 @@ async function runTests() {
         assertGreater(response.input_tokens, 10, 'input_tokens');
     });
 
+    // Test 16: Gemini model token counting
+    await test('Gemini model returns token count', async () => {
+        const response = await countTokensRequest({
+            model: 'gemini-3-flash',
+            messages: [
+                { role: 'user', content: 'Hello, how are you?' }
+            ]
+        });
+
+        assert(response.statusCode === 200, `Expected 200, got ${response.statusCode}`);
+        assertType(response.input_tokens, 'number', 'input_tokens');
+        assertGreater(response.input_tokens, 0, 'input_tokens');
+    });
+
+    // Test 17: Gemini model with system prompt and tools
+    await test('Gemini model with system prompt and tools', async () => {
+        const response = await countTokensRequest({
+            model: 'gemini-3-flash',
+            system: 'You are a helpful assistant.',
+            messages: [
+                { role: 'user', content: 'What is the weather in Tokyo?' }
+            ],
+            tools: [
+                {
+                    name: 'get_weather',
+                    description: 'Get weather for a location',
+                    input_schema: {
+                        type: 'object',
+                        properties: {
+                            location: { type: 'string' }
+                        }
+                    }
+                }
+            ]
+        });
+
+        assert(response.statusCode === 200, `Expected 200, got ${response.statusCode}`);
+        assertType(response.input_tokens, 'number', 'input_tokens');
+        assertGreater(response.input_tokens, 10, 'input_tokens for Gemini with tools');
+    });
+
     // Summary
     console.log('\n' + '═'.repeat(60));
     console.log(`Tests completed: ${passed} passed, ${failed} failed`);