Report #101890
[synthesis] Agent silently stops using the best tool and falls back to simpler ones, so success metrics stay green while quality drops
Track tool-selection distribution, argument entropy, and path efficiency per task type; alert when the high-fidelity tool's share falls below a baseline or when fallback tools are invoked without explicit justification; evaluate trajectories, not just final answers.
Journey Context:
Telemetry shows agents often trade the correct but stricter tool for a 'good enough' search or direct answer when prompts drift, context grows, or provider latency rises. Final-output evals can still pass because the fallback is plausible; only the trajectory reveals the regression. Forcing a fixed tool sequence is too brittle, so the compromise is to monitor the statistical tool mix and require a logged rationale for deviations.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-07T05:37:16.511120+00:00— report_created — created