Per-query or per-page performance broken down by month or week: the same matrix the app's Query Decay and Content Decay pages render (a row per query/page, one column per period). Use this to SEE how traffic trended period by period; use find_decaying_content instead when you only need decliners between two fixed ranges. Returns the top limit rows by total clicks, each with a values array aligned to periods for the chosen metric, plus a TOTALS-style per-period aggregate across all matched rows. Defaults to the last months complete months (through the end of last month). Served from the GSC Wizard ClickHouse warehouse when available (longer history, no GSC sampling), otherwise the live Search Console API (see dataSource). On the live API each period is read separately; truncated: true with a note means a period's read was capped or did not finish in time, and incompletePeriods lists any period that reads 0 because it was not read.