Will this fit my Asus laptop?

Only if your laptop uses part 18G241560005Q or a panel listed as compatible with it. Screen size alone is not enough; check the part number on the original panel's label and the connector type.

Is this an upgrade over my current screen?

No. It is a 1366x768 WXGA panel, the same class as the original on many budget 15.6-inch Asus laptops. It restores the original picture rather than improving it.

It is an LED-backlit LCD panel, the standard type in this size and resolution. It is not an OLED or mini-LED display.

Does it come with tools or instructions?

The listing covers the panel itself. Installation needs a compatible connector and the usual laptop disassembly tools, and the old panel's bracket and cable may need to be reused.

Is a 1366x768 screen good enough?

For web browsing, office work and video it is usable, but text is less sharp than on 1080p panels and there is less room on screen. It matches what these laptops were built for.