This is the mistake that hand-drawn footprints make most often. The mechanical drawing gives you the physical dimensions of the part: body size, lead length, lead width, pitch. The recommended land pattern is a separate drawing, and its pads are deliberately larger than the leads, sized to form a proper solder fillet at the toe, heel, and sides of each lead.
Copy the package outline dimensions into your pads and the part will physically fit while the joints are marginal. Building pads from the land pattern instead is what IPC-7351B is about, and it is the first thing to confirm in the pad table that comes back. When the datasheet has no land pattern at all, as with the AMS1117 above, the pads have to come from somewhere else, so check where.