fix: mcp schema generation test (#5608)

* base

* base

---------

Co-authored-by: Letta Bot <noreply@letta.com>

tests/mcp_tests/test_mcp_schema_validation.py

@@ -237,8 +237,12 @@ def test_mcp_schema_healing_with_anyof():
     assert strict_schema["strict"] is True
     assert "a" in strict_schema["parameters"]["required"]
     assert "b" in strict_schema["parameters"]["required"]  # Now required
-    # Type should be flattened array with deduplication
-    assert set(strict_schema["parameters"]["properties"]["b"]["type"]) == {"integer", "null"}
+    # anyOf should be preserved with integer and null types
+    b_prop = strict_schema["parameters"]["properties"]["b"]
+    assert "anyOf" in b_prop
+    assert len(b_prop["anyOf"]) == 2
+    types_in_anyof = {opt.get("type") for opt in b_prop["anyOf"]}
+    assert types_in_anyof == {"integer", "null"}
 
     # Validate strict schema
     status, _ = validate_complete_json_schema(strict_schema["parameters"])
@@ -246,7 +250,7 @@ def test_mcp_schema_healing_with_anyof():
 
 
 def test_mcp_schema_type_deduplication():
-    """Test that duplicate types are deduplicated in schema generation."""
+    """Test that anyOf duplicates are removed in schema generation."""
     mcp_tool = MCPTool(
         name="test_tool",
         description="A test tool",
@@ -270,10 +274,14 @@ def test_mcp_schema_type_deduplication():
     # Generate strict schema
     strict_schema = generate_tool_schema_for_mcp(mcp_tool, append_heartbeat=False, strict=True)
 
-    # Check that duplicates were removed
-    field_types = strict_schema["parameters"]["properties"]["field"]["type"]
-    assert len(field_types) == len(set(field_types))  # No duplicates
-    assert set(field_types) == {"string", "null"}
+    # Check that anyOf is preserved but duplicates are removed
+    field_prop = strict_schema["parameters"]["properties"]["field"]
+    assert "anyOf" in field_prop
+    types_in_anyof = [opt.get("type") for opt in field_prop["anyOf"]]
+    # Duplicates should be removed
+    assert len(types_in_anyof) == 2  # Deduplicated to 2 entries
+    assert types_in_anyof.count("string") == 1  # Only one string entry
+    assert types_in_anyof.count("null") == 1  # One null entry
 
 
 def test_mcp_schema_healing_preserves_existing_null():
@@ -333,7 +341,7 @@ def test_mcp_schema_healing_all_fields_already_required():
 
 
 def test_mcp_schema_with_uuid_format():
-    """Test handling of UUID format in anyOf schemas (root cause of duplicate string types)."""
+    """Test handling of UUID format in anyOf schemas (deduplicates but keeps format)."""
     mcp_tool = MCPTool(
         name="test_tool",
         description="A test tool with UUID formatted field",
@@ -353,11 +361,17 @@ def test_mcp_schema_with_uuid_format():
     # Generate strict schema
     strict_schema = generate_tool_schema_for_mcp(mcp_tool, append_heartbeat=False, strict=True)
 
-    # Check that string type is not duplicated
+    # Check that anyOf is preserved with deduplication
     session_props = strict_schema["parameters"]["properties"]["session_id"]
-    assert set(session_props["type"]) == {"string", "null"}  # No duplicate strings
-    # Format should NOT be preserved because field is optional (has null type)
-    assert "format" not in session_props
+    assert "anyOf" in session_props
+    # Deduplication should keep the string with format (more specific)
+    assert len(session_props["anyOf"]) == 2  # Deduplicated: string (with format) + null
+    types_in_anyof = [opt.get("type") for opt in session_props["anyOf"]]
+    assert types_in_anyof.count("string") == 1  # Only one string entry (the one with format)
+    assert "null" in types_in_anyof
+    # Verify the string entry has the uuid format
+    string_entry = next(opt for opt in session_props["anyOf"] if opt.get("type") == "string")
+    assert string_entry.get("format") == "uuid", "UUID format should be preserved"
 
     # Should be in required array (healed)
     assert "session_id" in strict_schema["parameters"]["required"]
@@ -408,7 +422,7 @@ def test_mcp_schema_healing_only_in_strict_mode():
 
 
 def test_mcp_schema_with_uuid_format_required_field():
-    """Test that UUID format is preserved for required fields that don't have null type."""
+    """Test that UUID format is preserved and duplicates are removed for required fields."""
     mcp_tool = MCPTool(
         name="test_tool",
         description="A test tool with required UUID formatted field",
@@ -428,11 +442,18 @@ def test_mcp_schema_with_uuid_format_required_field():
     # Generate strict schema
     strict_schema = generate_tool_schema_for_mcp(mcp_tool, append_heartbeat=False, strict=True)
 
-    # Check that string type is not duplicated and format IS preserved
+    # Check that anyOf is deduplicated, keeping the more specific version
     session_props = strict_schema["parameters"]["properties"]["session_id"]
-    assert session_props["type"] == ["string"]  # No null, no duplicates
-    assert "format" in session_props
-    assert session_props["format"] == "uuid"  # Format should be preserved for non-optional field
+    assert "anyOf" in session_props
+    # Deduplication should keep only the string with format (more specific)
+    assert len(session_props["anyOf"]) == 1  # Deduplicated to 1 entry
+    types_in_anyof = [opt.get("type") for opt in session_props["anyOf"]]
+    assert types_in_anyof.count("string") == 1  # Only one string entry
+    assert "null" not in types_in_anyof  # No null since it's required
+    # UUID format should be preserved
+    string_entry = session_props["anyOf"][0]
+    assert string_entry.get("type") == "string"
+    assert string_entry.get("format") == "uuid", "UUID format should be preserved"
 
     # Should be in required array
     assert "session_id" in strict_schema["parameters"]["required"]