Because a systematic or scoping review or other knowledge synthesis attempts to be rigorous and unbiased, readers must be able to replicate your searches.
The Cochrane Handbook (Section 6.6.2 Documenting and Reporting the Search Process) states the following:
Reporting the search process in the review abstract
The full search strategies for each database should be included in an Appendix of the review to avoid interrupting the flow of the text of the review. The search strategies should be copied and pasted exactly as run and included in full together with the line numbers for each search set.
Cochrane Handbook, Section 184.108.40.206. Reporting the Search Process in the Review
Guidelines, including a checklist for all items to include in your review, as well as a flow diagram reporting the number of studies found, de-duplicated and included in the reviw.
Guidelines for other types of reviews can be found at the EQUATOR Network
Guidelines for reporting the search strategy (e.g. databases searched, database interfaces, year ranges, grey literature, etc.) are under development: PRISMA-Search (PRISMA-S) Protocol (PDF)