Address PR comments: Add constants for context window sizes and expand test coverage

Co-Authored-By: Joe Moura <joao@crewai.com>

tests/test_gemini_2_5_support.py

@@ -1,6 +1,6 @@
 import pytest
 
-from crewai.llm import LLM
+from crewai.llm import LLM, CONTEXT_WINDOW_USAGE_RATIO, PRO_CONTEXT_SIZE
 
 
 def test_get_custom_llm_provider_gemini_2_5():
@@ -11,6 +11,31 @@ def test_get_custom_llm_provider_gemini_2_5():
 def test_gemini_2_5_context_window_size():
     """Test that the Gemini 2.5 model has the correct context window size."""
     llm = LLM(model="gemini-2.5-pro-exp-03-25")
-    from crewai.llm import CONTEXT_WINDOW_USAGE_RATIO
-    expected_size = int(2097152 * CONTEXT_WINDOW_USAGE_RATIO)
+    expected_size = int(PRO_CONTEXT_SIZE * CONTEXT_WINDOW_USAGE_RATIO)
     assert llm.get_context_window_size() == expected_size
+
+def test_gemini_2_5_invalid_model_name():
+    """Test handling of invalid model name variations."""
+    llm = LLM(model="gemini-2.5-wrong")
+    assert llm._get_custom_llm_provider() != "gemini"
+
+def test_gemini_2_5_model_parameters():
+    """Test model initialization with various parameters."""
+    llm = LLM(
+        model="gemini/gemini-2.5-pro-exp-03-25", 
+        temperature=0.7, 
+        max_tokens=1000
+    )
+    assert llm.model == "gemini/gemini-2.5-pro-exp-03-25"
+    assert llm.temperature == 0.7
+    assert llm.max_tokens == 1000
+
+def test_gemini_2_5_with_and_without_prefix():
+    """Test that the model works with and without the 'gemini/' prefix."""
+    llm_with_prefix = LLM(model="gemini/gemini-2.5-pro-exp-03-25")
+    llm_without_prefix = LLM(model="gemini-2.5-pro-exp-03-25")
+    
+    assert llm_with_prefix._get_custom_llm_provider() == "gemini"
+    assert llm_without_prefix._get_custom_llm_provider() == "gemini"
+    
+    assert llm_with_prefix.get_context_window_size() == llm_without_prefix.get_context_window_size()