Don't fix agent reliability by dumping more text into one instruction file. When you see a specific failure, add the smallest artifact that addresses it. This table maps the common failure modes to their fix and the file in this suite that implements it.
| Failure mode | What it looks like | Primary fix | Artifact |
|---|---|---|---|
| Cold-start confusion | A new session rediscovers setup/status from scratch | Make the repo the system of record | progress.md (+ harness-init) |
| Scope sprawl | Starts many features, finishes none; touches unrelated files | Restrict active scope to one feature | feature_list.json (WIP=1) |
| Premature completion | Claims "done" with no runnable proof | Bind completion to recorded evidence | clean-state-checklist.md, the verify path |
| Fragile startup | Every session re-learns how to boot the project | Standardize setup + verification | init.ps1 / init.sh |
| Weak handoff | Next session can't tell what's verified, broken, or next | End with an explicit handoff | session-handoff.md (via session-wrap) |
| Lost rationale | Agent undoes a deliberate choice after a reset | Persist the "why" outside chat | decisions.md |
| Context rot | Quality drops as the window fills with stale text/noise | Route + progressively disclose; reset over compaction | AGENTS.md as a map, docs/, context-management.md |
| Subjective review | "Looks good to me" review that depends on taste/memory | Score against fixed categories | /review-gate prompt-command |
| No clean exit | Repo decays; next session spends 30 min on rescue | Make clean state part of "done" | clean-state-checklist.md (via session-wrap) |
- Notice the actual symptom (not a vague "the agent is bad").
- Find the matching row.
- Add or strengthen that one artifact — most are already stamped by
harness-init; the fix is usually using it consistently via thesession-start/session-wraprituals. - Re-check after a couple of sessions. Treat the lowest-performing subsystem as the bottleneck, but confirm with real session outcomes before declaring victory.
See harness-model.md for the subsystem each artifact belongs to.