Welcome to PDF inserting. Yes, fuzziness.

First, check the PDF settings for resolution; a low resolution will contribute mightily to fuzziness. Beyond this, in my experience the route to optimum sharpness is a bit winding. I provide below a little guide I made for my department.

Best,
Ulodesk

While it produces unquestionably better quality to export the PDF to PNG files rather than JPEGs, the PNGs can remain quite large files. With Photoshop, there is a way, admittedly slightly longer, to reap the benefits of both quality and smaller size. My tests show a potentially significant file size decrease from the PNG route with similar quality.

1. Bring the PDF into Photoshop
2. Check the image size and adjust, if necessary, to fit on your Word page.
3. Crop and/or rotate to re-establish level horizontal if necessary
4. Open levels and adjust, if necessary. If you scanned from hard copy, this may be necessary in order to restore the type density. Depending on your document, you may find that input settings of about 70 for both black point and mid-tone, and perhaps 245 for white, may be about right (or use the black and/or white set-point droppers).
5. Export the document as a JPEG. If it is all text and line art, a quality setting of 4 may be adequate.
6. Open the new JPEG, enlarge the view, and check for quality.
7. A final check may be made by importing the JPEG into your doc, or a blank Word page, and printing the single page.