Existing Wording
The parameter _count is defined as a hint to the server regarding how many resources should be returned in a single page. Servers SHALL not return more resources than requested (even if they don't support paging) but are allowed to return less than the client asked for. Note that it is at the discretion of the search engine how to handle ongoing updates to the resources while the search is proceeding.

Proposed Wording
The parameter _count is defined as a hint to the server regarding how many resources should be returned in a single page. Servers SHALL not return more resources than requested (even if they don't support paging) but are allowed to return less than the client asked for. The server should repeat the original _count parameter in its returned page links so that subsequent paging requests honour the original _count. Note that it is at the discretion of the search engine how to handle ongoing updates to the resources while the search is proceeding.

Grahame's Comments
agree