A source is part of the interface

An answer is easier to use when a person can see where it came from.

Sources make an answer inspectable

A link to the relevant guide or policy lets a customer continue independently and lets a teammate check the response without guessing. The source is not an implementation detail. It is part of the interface between a company’s knowledge and the person asking for help.

Make the next step clear

The best source is not necessarily the longest document. It is the one that helps someone verify the answer or take the next action. Designing for that next step keeps retrieval focused on usefulness rather than volume.