fix: make composition keywords private

Author: Murat Kaan Meral

src/strands/tools/registry.py

@@ -23,7 +23,7 @@
 from ..experimental.tools import ToolProvider
 from ..types.tools import AgentTool, ToolSpec
 from .loader import load_tool_from_string, load_tools_from_module
-from .tools import COMPOSITION_KEYWORDS, PythonAgentTool, normalize_schema, normalize_tool_spec
+from .tools import _COMPOSITION_KEYWORDS, PythonAgentTool, normalize_schema, normalize_tool_spec
 
 logger = logging.getLogger(__name__)
 
@@ -602,7 +602,7 @@ def validate_tool_spec(self, tool_spec: ToolSpec) -> None:
             if "$ref" in prop_def:
                 continue
 
-            has_composition = any(kw in prop_def for kw in COMPOSITION_KEYWORDS)
+            has_composition = any(kw in prop_def for kw in _COMPOSITION_KEYWORDS)
             if "type" not in prop_def and not has_composition:
                 prop_def["type"] = "string"
             if "description" not in prop_def:

src/strands/tools/tools.py

@@ -17,9 +17,11 @@
 
 logger = logging.getLogger(__name__)
 
-# JSON Schema composition keywords that define type constraints.
-# Properties with these should not get a default type: "string" added.
-COMPOSITION_KEYWORDS = ("anyOf", "oneOf", "allOf", "not")
+_COMPOSITION_KEYWORDS = ("anyOf", "oneOf", "allOf", "not")
+"""JSON Schema composition keywords that define type constraints.
+
+Properties with these should not get a default type: "string" added.
+"""
 
 
 class InvalidToolUseNameException(Exception):
@@ -92,7 +94,7 @@ def _normalize_property(prop_name: str, prop_def: Any) -> dict[str, Any]:
     if "$ref" in normalized_prop:
         return normalized_prop
 
-    has_composition = any(kw in normalized_prop for kw in COMPOSITION_KEYWORDS)
+    has_composition = any(kw in normalized_prop for kw in _COMPOSITION_KEYWORDS)
     if not has_composition:
         normalized_prop.setdefault("type", "string")
     normalized_prop.setdefault("description", f"Property {prop_name}")