You'll notice
File paths in remote tool results are rewritten to ./ or ~/ shorthand when they sit under the working or home directory.
When a tool call result carries a file_path matching the session's known working directory or home directory, the remote-tool-call path now rewrites it to a ./ or ~/ relative form before returning or tracking it. This is controlled by a new backfillObservableInput capability on the tool and working_dir/home_dir descriptions on the host.