feat: use json schema for tool argument serialization

- Replace Python representation with JsonSchema for tool arguments
  - Remove deprecated PydanticSchemaParser in favor of direct schema generation
  - Add handling for VAR_POSITIONAL and VAR_KEYWORD parameters
  - Improve tool argument schema collection

lib/crewai/tests/tools/test_tool_usage.py

@@ -107,25 +107,20 @@ def test_tool_usage_render():
 
     rendered = tool_usage._render()
 
-    # Updated checks to match the actual output
+    # Check that the rendered output contains the expected tool information
     assert "Tool Name: Random Number Generator" in rendered
     assert "Tool Arguments:" in rendered
-    assert (
-        "'min_value': {'description': 'The minimum value of the range (inclusive)', 'type': 'int'}"
-        in rendered
-    )
-    assert (
-        "'max_value': {'description': 'The maximum value of the range (inclusive)', 'type': 'int'}"
-        in rendered
-    )
     assert (
         "Tool Description: Generates a random number within a specified range"
         in rendered
     )
-    assert (
-        "Tool Name: Random Number Generator\nTool Arguments: {'min_value': {'description': 'The minimum value of the range (inclusive)', 'type': 'int'}, 'max_value': {'description': 'The maximum value of the range (inclusive)', 'type': 'int'}}\nTool Description: Generates a random number within a specified range"
-        in rendered
-    )
+
+    # Check that the JSON schema format is used (proper JSON schema types)
+    assert '"min_value"' in rendered
+    assert '"max_value"' in rendered
+    assert '"type": "integer"' in rendered
+    assert '"description": "The minimum value of the range (inclusive)"' in rendered
+    assert '"description": "The maximum value of the range (inclusive)"' in rendered
 
 
 def test_validate_tool_input_booleans_and_none():