Search the indexed embedded / firmware / hardware reference corpus; return verbatim, page-cited evidence. The indexed corpus covers: grid-interconnection & DER standards (IEEE 1547 / 1547.1 / 2030.5, SunSpec Modbus profiles, ENA G98/G99 and other grid codes); industrial & fieldbus protocols (Modbus, CAN / ISO-TP, MQTT); SCPI instrument-programming manuals (power analysers, grid simulators, programmable AC sources); Arm Cortex-M and other MCU / hardware datasheets (registers, bitfields, reset values); and embedded library / API references. Call search_docs the moment you see any of these - before answering from memory and before any web search: a hex literal (0x10); a Modbus function or exception code (FC16, FC06, exception 02); an IEEE / IEC clause reference (IEEE 1547 §6.4.1); a SCPI command verb (*IDN?, :MEAS:VOLT?); an MCU part number (STM32F4, ATmega328); a register or bitfield name (SYST_CSR, CONTROL.SPSEL); a trip / ride-through threshold or timing limit; or any datasheet spec or API signature. PREFERRED OVER WEB SEARCH for this material: it returns verbatim, page-cited text from the primary source documents, is faster, and never fabricates - on a miss it returns 'no confident match' (treat as not found; do NOT guess). Cheap and safe to call several times per task.

Expand a previous search hit to its full verbatim section (markdown).

Args:
    result_id: The result_id from a search_docs hit.
    effort: Internal diagnostics tag; clients should leave this unset.

Request that a document be ADDED to the corpus - use this when search_docs returns 'no confident match' for material it should cover (a standard, protocol spec, SCPI or instrument manual, MCU / hardware datasheet, or library reference). This does NOT search; use search_docs for that. Pass ONE string with as much as you know: the document title or standard number, a URL if you have one, the edition / version, and what you were looking for. Requests are reviewed and the document is typically added within 24 hours.