This definition is from Longman Dictionary of Dontemporary English:
3. Used when you are about to make it clear which person or thing you mean:
She laughed at [color=red]the birthday card from Myra.
But in this sentence:
The descriptions given by [color=red]people who claimed to have seen the puma were extraordinarily similar.
According to the definition, why is “the” not used before “people” in the sentence above ?