My Slack bot was firing success messages while D1 row count sat completely frozen. The agent wasn't crashing — it was completing its Slack notification step and skipping all the actual work. Alerts alone would never have caught this.
The fix was treating Slack, D1 logging, and cost tracking as one connected pipeline instead of three separate tools. The schema I landed on is deliberately lean — 7 columns, with tokens_used being the one that matters most:
CREATE TABLE agent_runs (
id TEXT PRIMARY KEY,
agent_name TEXT NOT NULL,
