Short answer: electricals need to be clean, complete (plug and cable intact), and PAT-testable for a shop to sell them. If it's broken beyond that, it needs a WEEE recycling point, not a charity shop.
Drills, sanders, jigsaws and the rest follow exactly the same rule as any other electrical: clean, complete with cable and any battery, and PAT-testable before a shop can sell it. Hand tools — spanners, screwdrivers, hand saws — aren't electrical at all, so they're judged the same way as other bric-a-brac: clean, functional, and not badly rusted.
Check the shops currently accepting electricals before you make the trip — not every shop tests and sells them.