Method Map

This table maps the most common long-running coding-agent failure modes to the artifact or operating rule that usually fixes them first.

Failure mode	What it looks like in practice	Primary fix	Supporting artifact
Cold-start confusion	A new session spends most of its time rediscovering setup and status	Make the repository the system of record	claude-progress.md
Scope sprawl	The agent starts several features and finishes none of them cleanly	Restrict active scope	feature_list.json
Premature completion	The agent claims done after code edits but before runnable proof	Bind completion to evidence	clean-state-checklist.md
Fragile startup	Every session re-learns how to boot the project	Standardize setup and verification	init.sh
Weak handoff	The next session cannot tell what is verified, broken, or next	End with an explicit handoff	session-handoff.md
Subjective review	Review quality depends on taste or memory	Score output with fixed categories	evaluator-rubric.md

Operating Principle

Add the smallest artifact that directly addresses the observed failure mode. Avoid solving every reliability problem by dumping more text into one global instruction file.