Major Today a client specifies that they want a count of entities returned inline by specifying the query option $inlinecount=allpages.
the value "allpages" is meaningless and implies there is some other "singlepage" or "mostpages" or "everyotherpage" option.
As this option is boolean, "yes"/"no" or "true"/"false" would be more natural values.
We could even omit the "value" and make presence of this option sufficient:
GET ~/Customers?$inlinecount
It is good suggestion.
However, $inlinecount sets the expectation that server returns the exact count. But sometimes exact count may not be available or to compute exact count server needs to make multiple calls on data source that in worst case can take the double the time
For instance, server has to make enumerate() call to get entities because server has huge dataset for requested query. So, it can return one page with reasonable dataset size and include link to the next page with $skiptoken. In this case if request includes $inlinecount then server has to make enumerate() call twice, one for count and second for data.
How to convey to the client that returned count is approximate value and count value may be changed in the next page?