return Math.max(1, opts?.maxToolResultChars ?? DEFAULT_MAX_LIVE_TOOL_RESULT_CHARS);

}

// `details` is runtime/UI metadata, not model-visible tool output. Keep the

// session JSONL useful for debugging without letting metadata blobs dominate

// disk, replay repair, transcript broadcasts, or future tooling that reads raw

// sessions. Model-visible text belongs in tool result `content`.

const MAX_PERSISTED_TOOL_RESULT_DETAILS_BYTES = 8_192;

const MAX_PERSISTED_DETAIL_STRING_CHARS = 2_000;

const MAX_PERSISTED_DETAIL_SESSION_COUNT = 10;

originalSize: BoundedJsonUtf8Bytes,

sanitizedBytes?: number,

): Record<string, unknown> {

// If even the structured summary is too large, keep only shape and stable

// status fields. This preserves "what happened?" without persisting the raw

// diagnostics payload that caused the cap to trip.

const fallback: Record<string, unknown> = {

persistedDetailsTruncated: true,

finalDetailsTruncated: true,

if (details === undefined || details === null) {

return details;

}

// Measure with an early-exit walker so hostile or enormous details do not

// need to be fully stringified just to learn they exceed the persistence cap.

const originalSize = boundedJsonUtf8Bytes(details, MAX_PERSISTED_TOOL_RESULT_DETAILS_BYTES);

if (originalSize.complete && originalSize.bytes <= MAX_PERSISTED_TOOL_RESULT_DETAILS_BYTES) {

return details;