Function formatToolResultAsText

packages/mcp-server/src/format.ts:156–186

(content: string)

 * Returns null if the content is not suitable for text formatting.
 */
export function formatToolResultAsText(content: string): string | null {
  let parsed: unknown
  try {
    parsed = JSON.parse(content)
  } catch {
    return null
  }

  if (!parsed || typeof parsed !== 'object') return null
  const obj = parsed as Record<string, unknown>

  // If there's a messages array with senderName/content/timestamp, format it
  if (Array.isArray(obj.messages) && obj.messages.length > 0) {
    const msgs = obj.messages as FormattableMessage[]
    if (msgs[0] && 'senderName' in msgs[0] && 'timestamp' in msgs[0]) {
      return formatObjectWithMessages(obj, msgs)
    }
  }

  // If there are ranking/keywords arrays, format as numbered list
  if (Array.isArray(obj.ranking) || Array.isArray(obj.keywords)) {
    return formatArrayResult(obj)
  }

  // If there are sessions, format them compactly
  if (Array.isArray(obj.sessions)) {
    return formatSessionsList(obj)
  }

  return null
}

function formatObjectWithMessages(obj: Record<string, unknown>, msgs: FormattableMessage[]): string {
  const lines: string[] = []