Tool steel is rarely chosen because it is easy. It is chosen because the end part needs to survive repeated contact, abrasion, loading, or production wear without losing function too quickly. That makes it especially relevant for tooling, fixture hardware, and industrial replacement parts.
The most important early question is whether the part should be machined soft and heat-treated later, or machined closer to final hardness with a more conservative process plan. That decision affects cost, timing, and tolerance strategy.