docs: clarify get_file_names_tool returns files only, not folders

Make the tool description explicit that the tool lists only regular files
and never includes folders/subdirectories, so the agent does not try to use
it to discover or navigate directories.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: philipph-askui

src/askui/tools/store/computer/experimental/get_file_names.py

@@ -28,9 +28,11 @@ def __init__(self, agent_os: ComputerAgentOS | None = None) -> None:
             name="get_file_names_tool",
             description=(
                 "Lists the names of regular files in an absolute directory on the "
-                "computer under automation. Subdirectories are not included—only "
-                "files are returned. Use absolute paths as on the target machine. "
-                "Returns names only; use get_file_tool to read a file's contents."
+                "computer under automation. IMPORTANT: only files are returned - "
+                "folders and subdirectories are NOT included in the result and this "
+                "tool cannot be used to discover or navigate them. Use absolute "
+                "paths as on the target machine. Returns names only; use "
+                "get_file_tool to read a file's contents."
             ),
             input_schema={
                 "type": "object",