nx_tool_ping.nx

nx_tool_ping.nx -- the canonical no-op smoke-test organ for the executable API. It does exactly one thing: print a fixed sentinel and exit 0. Zero inputs, zero side effects, no files, no network -- so it is the SAFE tool to put on the execution allowlist (nx_tool_exec_allow) first, to prove /mcp tools/call really forks+captures a real organ end-to-end without risking anything. license_tier: ORIGINAL expect_exit: 0