Keep one canonical log.
The format
A single TSV file, one row per decision. Cells stay single-line. Evidence is a pointer, not prose.
Copy references/decision-log-template.tsv (the header row) to start a clean log. Columns:
- ts. ISO8601 timestamp.
- phase. The phase or workstream.
- decision. What was chosen or done, one line.
- why. The reason in plain words. If a principle drove it, say it plainly, not as a jargon tag.
- evidence. A link or path that proves it: commit SHA, PR number,
file:line, or an artifact, trace, or screenshot path. Never a paragraph. - result. The outcome or predicate state:
tests green,reverted,pixel-diff 0,INCONCLUSIVE,open.
An example, plain-spoken so a reviewer reads it at a glance.
ts phase decision why evidence result
2026-05-24T09:02:00Z frame counted the work first, about 100 components and roughly 75 hours wanted to know the size before starting a long run commit 3a9f1c2 found 5 things to sort out before starting
2026-05-24T09:40:00Z harness took screenshots of the old version before changing anything so we can compare old against new and catch any visual change scripts/snapshot.sh, baseline/ saved 120 reference screenshots
2026-05-24T11:15:00Z widget moved the widget styles over without changing how it looks keep the change small and the result identical commit 7c21e0a, pixel-diff 0 looks identical, tests pass
2026-05-24T12:30:00Z widget threw out a helper's work because its screenshots were blank checked the real files instead of trusting its summary worktree reset reverted, tightened the instructions for next time
Logging a row
Write each entry the way you'd tell a teammate what you did. Plain words, concrete actions, no AI speak or abstract jargon. Use the unslop skill on log text too.
Use the helper scripts/log.sh <logfile> <phase> <decision> <why> <evidence> <result>. It stamps ts, writes the header on first use, strips stray tabs/newlines, and prefixes any cell starting with =, +, -, or @ with a single quote. A bare printf appending a row works too, but mind those same bytes if cells come from generated or user-supplied text.
Log decision points and checkpoints, not every action: a fork chosen, a unit completed with its verification result, a pivot or revert with its trigger, a blocker surfaced, a gate fixed. For loop runs, one row per iteration. Skip the trivial and self-evident.
A run is one agent conversation, including its later turns and any summary of it. A pickup, a replacement agent, or a new chat starts a new run. When a run adds to a log that already has rows, its first row has phase start, and so does its first row after another run's start row. So a run that comes back to a log in a later turn first reads the log's last rows to see whether another run wrote since. A start row names the ts range of the rows before it that this run did not write, and its evidence names this run, such as its agent id. Use phase start for nothing else.
Where it lives
By default the log is a working artifact, not committed. Keep it at decisions.tsv in the work dir, or .audit/<task-slug>.tsv when several efforts run at once, and leave it out of git.
Commit it only when the work is ambitious enough that a reviewer needs the trail to trust the result.
Rules
- Append-only. A wrong call gets a new row that supersedes it. Never edit or delete history.
- Prefer evidence produced by committed scripts over hand-made one-offs (the encode-lessons-in-structure principle skill).
Audit the log against the transcript
At the end of the run, before handing back, check the log told the truth. Read this run's transcript from this workspace's session store. Use the pstack-harness skill to locate it. Don't read other workspaces' stores. That reads unrelated private chats. If you cannot find or read this run's transcript, do not walk the rows. Say in the Attention section that the audit did not run, so the log is unchecked against the transcript. Otherwise, walk this run's rows against what actually happened. Each stretch of them begins at one of this run's start rows, or at the first row if this run created the log, and ends at the next start row of another run:
- Check that every row maps to a real decision or action.
- Check that each row's evidence resolves and shows what the row claims.
- A fork, pivot, or abandoned approach that shaped the work but isn't logged is a gap. Add it.
Correct the log, not the story. The audit never edits or removes a row, even an invented one. When a row records neither a real decision nor a real action, or its claim or evidence is wrong, add a row that supersedes it with what actually happened and a pointer that resolves. This audit does not check rows outside this run's stretches. If this run's own work shows one of them is wrong, supersede it like any wrong call.
Cross-model review of the trail
Before handing back, spawn a reviewer subagent on the trail reviewer role. Use the pstack-harness skill's Spawn a role section to resolve the role. Follow that section for the spawn call and for execution-identity disclosure in the verdict and reply. Never pick a model that the resolver's output does not name. Self-review is not a substitute. The subagent reads the audit trail and the run's transcript, then flags what the user should pay attention to. Not a redo of the work, a scan for what's suboptimal or risky.
- Decisions logged with weak or absent evidence.
- Verification steps skipped or claimed without proof in the transcript.
- Choices that look risky in hindsight (premature, scope-creeping, papering over a symptom).
- Gaps the user would otherwise miss on a casual skim.
Every reply for a run that produced a trail ends with an "Attention" section. Lead with the reviewer's model and effort on its own line (reviewed by <model>@<effort>, and the role it came from when it was not trail reviewer), then list each flag pointing to specific rows or moments. "No flags" is a valid value. The model name is not.
Reviewing the trail
Read top to bottom, follow the evidence pointers, spot-check. GitHub renders a committed TSV as a table. column -s$'\t' -t decisions.tsv renders it in a terminal.
Composing this skill
Other skills route their audit trail here instead of inventing one. Reference it by name and let it own the format. Don't restate the columns.