chore: import upstream snapshot with attribution

tests/resources/agents/async-tools/tools/python/count_chars.py

@@ -0,0 +1,16 @@
+"""count_chars fixture tool (sync; returns character count)."""
+
+from __future__ import annotations
+
+from omnigent_client.tools import tool
+
+
+@tool
+def count_chars(text: str) -> int:
+    """
+    Return the literal character count of ``text``.
+
+    :param text: Text to measure, e.g. ``"abc"``.
+    :returns: Length of ``text``, e.g. ``3``.
+    """
+    return len(text)