On 17 September 1804 there's a burial in All Saints, Dewsbury, for "James Tolson, son of Richard". Can I assume, from this wording, that James was a child?
Personally I wouldn't automatically assume that. If his father had siblings they may have named one of their sons James as well if they followed the practice of naming a son after their father and the vicar would distinguish them by adding the father's name, even when they were adults.
Some trees show this James as the James Tolson who had married Priscilla Richardson. Am I right to discard this possibility, given the identification as "son of Richard"?
I would be more inclined to dismiss the marriage as I would have expected the phrase 'Husband/Widower of <name of wife>' but the vicar may have been particularly patriarchal in his outlook and entered the father's name as a matter of course. However I wouldn't entirely rule it out.
Have a look at other entries and see what the general style of entry was.
Data from on-line trees
should be treated with extreme caution especially if there are no documents quoted to back it up. Even then that documentary evidence needs to be examined very carefully.
I would look for a Baptism of 'James, son of Richard Tolson (and <name of mother>)' and a Marriage entry. If he was married the Baptism could be 18/20yrs earlier and maybe even more.
Even if you do find a marriage it may not be the same James Tolson. (see comment above about naming sons.)
Parish Records at this time are notoriously erratic in the details they give concerning marriages, some will simply say 'James Tolson married.' not even mentioning the bride, others will name both parties and their fathers and some will include the mothers' names as well if you are very lucky.
I wish you the best of luck in your efforts to solve the conundrum.