Your agent needs to know exactly how to extract its score. The evaluation directive specifies the grep command:
grep "^val_bpb:\|^peak_vram_mb:" run.log
If grep returns values, training completed. If it returns empty, the run crashed. This binary check is how your agent distinguishes a failed experiment from a successful one.
The directive also sets the timeout: kill any run that exceeds minutes total. This catches experiments where the agent accidentally creates an infinite loop or a model so large that compilation alone takes longer than training.