Suppliers scan drawings for risk signals: tight geometric tolerances, surface finish on hard-to-access faces, deep pockets with small corner radii, and thread depth requirements that drive tap selection.
Start with the title block: material, heat treat note, finish, and revision. Then follow datum references—if datums conflict with functional assembly needs, fix it before quote, not after first article.
General tolerance blocks are helpful, but overusing tight local callouts without justification can inflate cost. Mark true critical features explicitly so programming and inspection focus where it matters.
For assemblies, include a bill of materials or reference only if it affects the machined component; otherwise keep the scope to the single part to avoid ambiguity.