Detectors overview

Each detector looks for one pattern within a stream and estimates its avoidable cost in token-equivalents.

Detector	Key	What it finds	Counted in grade
Idle cache rebuild	idle_cache_rebuild	The cache expired during a break and the context was re-written	Yes
Uncached context	uncached_context	Claude conversations re-sent without prompt caching	Yes
Uncached context, self-hosted	uncached_context_self_hosted	The same on non-Claude models	No (informational)
Re-read	reread	A file read again with no change in between	Yes
Duplicate call	duplicate_call	An identical search or fetch repeated	Yes
Huge result	huge_result	A tool output over 10k tokens, carried in every later message	Yes
Error thrash	error_thrash	The same tool failing 3+ times in a row	Yes

The key is how each detector appears in the JSON output.