The lack of clarity is due to overscan. Television signals have historically been larger than the screen, because screen sizes were not exact. To avoid cutting off part of the image, the driver scales the image down so that it all fits on the screen.
The only way to avoid that is to set your television to a scaling mode that does not use overscan. It will typically be found in the aspect ratio settings. The name will be something other than 16:9, Stretch, Full, etc. It might be Normal, Screen Fit, or some other name suggesting no overscan. Some televisions actually have an explicit overscan option which can be turned off. You'll have to look up how to do it on your specific model, if it's possible.
Not all televisions can disable overscan. If yours cannot, then you will not be able to get clear text using it as a monitor, at least over HDMI. Some televisions have VGA inputs, which implicitly don't use overscan.
That's about all I can say without knowing any details about your setup beyond the graphics card.
