This passage in Ryan Singer’s book, Shape Up resonated:

Stay debt-free

It can be tempting to commit to making changes in response to feedback, but then you no longer have a clean slate for the next cycle. Remember: these are just raw ideas coming in. The way to handle them is with a gentl “no”. Saying “no” doesn’t prevent you from continuing to contemplate them and maybe shape them up into future projects. Saying “yes,” on the other hand takes away your freedom in the future. It’s like taking on debt.

It seems in the context of responding to requests there’s a big difference between yes and no.

Saying yes commits you to a path - whether you have all of the information necessary to make that decision or not.

Saying no leaves the opportunity open to revisit the problem later if done politely - perhaps after you’ve taken the time to understand the problem more fully.

Ultimately, the customer wants a solution to their problem, but taking on an obligation of unknown size is imprudent.

To Ryan’s point, better to stay debt-free if you can.