Did Britain have a formal alliance obligation to France?

Was prewar Britain careful to avoid formal obligations toward France?

Yes; the Entente Cordiale was an understanding, not a formal alliance commitment.

Britain avoided binding itself through a formal alliance before the war. The name Entente Cordiale matters: it described an understanding and improving relationship, not the same legal commitment as an alliance. That distinction helps explain both cooperation and lingering British uncertainty about relying on the French fleet.