wfx_test_agent is a script used for RF testing, as described in https://github.com/SiliconLabs/wfx-common-tools/blob/HEAD/test-feature/README.md
Details on the wfx_test_agent are given in https://github.com/SiliconLabs/wfx-common-tools/blob/HEAD/test-feature/README.md#dut-wfx_test_agent-installation