Addiction worker Linda McCulloch told a Fatal Accident Inquiry at Paisley Sheriff Court that when she went to see him and his mother Kimberley in April 2009, he was smartly dressed in a three-piece outfit from retailer Next.
Speaking of the home visit, which took place within a week of Declan's first birthday, she said: "He had a tank-top, trousers and a T-shirt on.
"I had seen that outfit in the Next catalogue and said that to Kimberley. She said that was where it was from."
Ms McCulloch, who had gone to visit Hainey at her Paisley home along with fellow addictions worker Jill Stevenson, said there was "nothing to suggest there was any evidence of neglect".
She added: "When I went in Declan was in his playpen with his bottle of milk. I usually say 'hello', do a bit of baby talk and say 'you're lovely' and that's what I did. He did look at me and acknowledge me."
She also told the court she thought Declan looked pale, but said some people just have a pale complexion. She said there was nothing in the interaction between Kimberley and Declan that caused her concern.
The home visit, at Hainey's flat in Bruce Road, Paisley, was a planned meeting on April 21, 2009.
The day before, Ms McCulloch had gone to the flat to conduct an unplanned visit. But there was no answer at the door.
Once she got inside the next day, Ms McCulloch said she thought the house was "clean and it was tidy".
The inquiry is trying to establish exactly how Declan died. His decomposing body was found in a litter-filled cot in March 2010. His mother was later jailed for life after being convicted of murdering him, but was released on appeal in April 2013.
The inquiry continues.