Function estimateTokens

src/utils/compaction.ts:68–89

(messages: Message[])

Drop:
- Greetings, pleasantries, acknowledgments
- The agent's intermediate narrations ("let me look at..." / "now I'll...")
- Long tool outputs (replace with "[examined X]" if relevant)
- Code blocks longer than 3 lines (replace with a 1-line description)

Output format: plain markdown, 200-500 tokens TOTAL. Start with "${SUMMARY_PREFIX}".
DO NOT explain what you're doing — just produce the summary.`;

export function estimateTokens(messages: Message[]): number {
  let total = 0;
  for (const m of messages) {
    const content: any = m.content;
    if (typeof content === 'string') total += countTokens(content);
    else if (Array.isArray(content)) {
      for (const part of content) {
        if (typeof part === 'object' && part && 'text' in part && typeof part.text === 'string') {
          total += countTokens(part.text);
        }
      }
    }
    if ('tool_calls' in m && Array.isArray((m as any).tool_calls)) {
      for (const tc of (m as any).tool_calls) {
        total += countTokensJson(tc);
      }
    }
    // Per-message overhead (role tags, delimiters) — ~4 tokens each in chat formats.