If your dog gets out, can whoever finds them reach you?

A microchip is the backup, not the fast route. It can only be read with a scanner, which means whoever finds your dog has to get them to a vet or a shelter first — and that depends on them having the time and inclination to do it. A tag they can simply read lets them phone you from where they're standing. Have both.

A phone number is the one thing that matters — ideally a mobile you actually answer. Add a second number if you can. Some owners deliberately leave the pet's name off, on the reasoning that a stranger who can call your dog by name has an easier time coaxing them away; others want the name there so a finder can reassure a frightened animal. Both are defensible, so decide which risk bothers you more.

Engraved metal outlasts printed text, but any tag that swings against a collar buckle will dull eventually. Check it every few months — a tag you can no longer read is the same as no tag at all, and it's the failure people don't notice until it matters.

These are made to order rather than held in stock, so allow a few days for production on top of shipping. If your dog currently has no ID at all, put a cheap temporary tag on today and treat this as the permanent replacement.