feat: Enhance Bedrock authentication with improved docs, validation, and tests

- Add clearer authentication method comments in documentation examples
- Include security best practices for API key usage
- Add CLI validation hints for AWS Bedrock API key format
- Implement comprehensive error handling tests (timeout, rate limit, invalid key)
- Add connection error and retry scenario test cases
- Maintain consistency between English and Portuguese documentation

Addresses AI code review feedback on PR #3126

Co-Authored-By: Jo\u00E3o <joao@crewai.com>

tests/test_bedrock_authentication.py

@@ -1,4 +1,5 @@
 import os
+import pytest
 from unittest.mock import patch, MagicMock
 from crewai import LLM
 
@@ -106,3 +107,71 @@ class TestBedrockAuthentication:
         
         mock_completion.assert_called_once()
         assert result == "Test response"
+    @patch.dict(os.environ, {
+        'AWS_BEARER_TOKEN_BEDROCK': 'test-api-key',
+        'AWS_DEFAULT_REGION': 'us-east-1'
+    })
+    @patch('litellm.completion')
+    def test_bedrock_timeout_handling(self, mock_completion):
+        """Test Bedrock API timeout handling."""
+        mock_completion.side_effect = TimeoutError("Request timed out")
+        
+        llm = LLM(model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0")
+        with pytest.raises(TimeoutError, match="Request timed out"):
+            llm.call("test message")
+
+    @patch.dict(os.environ, {
+        'AWS_BEARER_TOKEN_BEDROCK': 'test-api-key',
+        'AWS_DEFAULT_REGION': 'us-east-1'
+    })
+    @patch('litellm.completion')
+    def test_bedrock_rate_limit_handling(self, mock_completion):
+        """Test Bedrock API rate limit handling."""
+        mock_completion.side_effect = Exception("Rate limit exceeded")
+        
+        llm = LLM(model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0")
+        with pytest.raises(Exception, match="Rate limit exceeded"):
+            llm.call("test message")
+
+    @patch.dict(os.environ, {
+        'AWS_BEARER_TOKEN_BEDROCK': 'invalid-key',
+        'AWS_DEFAULT_REGION': 'us-east-1'
+    })
+    @patch('litellm.completion')
+    def test_bedrock_invalid_api_key(self, mock_completion):
+        """Test Bedrock with invalid API key."""
+        mock_completion.side_effect = Exception("Invalid API key")
+        
+        llm = LLM(model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0")
+        with pytest.raises(Exception, match="Invalid API key"):
+            llm.call("test message")
+
+    @patch.dict(os.environ, {
+        'AWS_ACCESS_KEY_ID': 'test-key-id',
+        'AWS_SECRET_ACCESS_KEY': 'test-secret-key',
+        'AWS_DEFAULT_REGION': 'us-east-1'
+    })
+    @patch('litellm.completion')
+    def test_bedrock_connection_error(self, mock_completion):
+        """Test Bedrock with connection error."""
+        mock_completion.side_effect = ConnectionError("Connection failed")
+        
+        llm = LLM(model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0")
+        with pytest.raises(ConnectionError, match="Connection failed"):
+            llm.call("test message")
+
+    @patch.dict(os.environ, {
+        'AWS_BEARER_TOKEN_BEDROCK': 'test-api-key',
+        'AWS_DEFAULT_REGION': 'us-east-1'
+    })
+    @patch('litellm.completion')
+    def test_bedrock_api_key_with_retry_scenario(self, mock_completion):
+        """Test Bedrock API key authentication with retry scenario."""
+        mock_completion.side_effect = [
+            Exception("Temporary error"),
+            MagicMock(choices=[MagicMock(message=MagicMock(content="Success after retry"))])
+        ]
+        
+        llm = LLM(model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0")
+        with pytest.raises(Exception, match="Temporary error"):
+            llm.call("test message")