I was looking at the wizard spell summon monster. It states the summoned monster has 1 HP. Doesn't that mean that it will die really easily? I guess the "Its bond to your plane is strong: +2 HP for each level you have" makes it usable if you pick that.
Yes, the spell is very flexible. It's not just for summoning combat chumps.
The base creature is something small and weak. That's good! It means that if what you need is an tiny rat, not a big tiger, the spell is still useful.
If you need a combat critter, pick your 1d6 extra features appropriately: the extra HP, extra damage, +2 STR (for H&S), maybe a useful feature like tough hide or poison. What features you choose determines what actual monster results from the spell:
The GM will tell you the type of monster you get based on the traits you select.
But if you need an owl to spy for you, pick flight and night vision instead.