| name | document-agent-failure |
| description | Records unexpected agent behavior or failures to a persistent ledger at building_knowledge_and_agent/agents-failure.md. Use when the user reports that an agent, subagent, skill, hook, or the lead agent itself behaved unexpectedly, ignored a rule, produced wrong output, or skipped a documented step. Groups similar failures by a loose fingerprint and prompts the user to fix the root cause once the same failure type has been observed three times. |
Document Agent Failure
Maintain a ledger of agent failures so recurring problems become visible and get fixed at the root cause instead of being silently re-encountered.
Ledger Location
/path/to/works/for/you/knowledge_base/projects/building_knowledge_and_agent/agents-failure.md
If the file does not exist, create it from the Initial Ledger Template below before adding the first entry.
When to Use
Trigger this skill whenever:
- The user complains that an agent / subagent / skill / hook behaved unexpectedly
- An agent ignored a workflow rule, memory item, or CLAUDE.md instruction
- A skill produced wrong output, hallucinated context, or skipped documented steps
- The user says things like "this isn't right", "you shouldn't have done that", "the X agent failed", "you forgot to ..."
- You yourself notice a clear deviation from documented behavior that the user has not yet flagged
Do not trigger for:
- Bugs in user code or third-party tools (those are not agent failures)
- One-off LLM nondeterminism the user shrugs off
- Cases where the user explicitly says "don't bother documenting this"
If unsure, ask: "Want me to log this in the agent failure ledger?"
Workflow
- Read the ledger to load existing failure types and their counts.
- Classify the current failure:
- Identify the failing component (specific agent name, skill name, hook, or
lead-agent)
- Write a one-line normalized summary
- Generate a fingerprint:
<component>:<short-kebab-slug> (see Fingerprint Conventions)
- Match against existing OPEN entries using a loose heuristic — prefer grouping over splitting. If the same component is failing for what plausibly looks like the same root cause, reuse the existing fingerprint. If clearly distinct, create a new entry.
- Update the ledger:
- Match found → append a new occurrence line (date + brief context) and increment
count
- No match → create a new entry under
## Open with status: open, count: 1
- Check the count for that entry after updating:
count < 3 → save and confirm to user with a one-line notecount == 3 → emit the Three-Strike Prompt inline to the usercount > 3 → also emit the prompt, more urgently, and note in the message that the entry is past the threshold
- On confirmed fix → follow Retiring an Entry.
Entry Schema
Each entry is a level-3 markdown section under ## Open:
### <fingerprint>
- **status**: open
- **component**: <agent / skill / hook name, or `lead-agent`>
- **summary**: <one-line normalized description of the failure>
- **first-seen**: YYYY-MM-DD
- **count**: N
- **occurrences**:
- YYYY-MM-DD — <one-line context: session topic / triggering prompt / observed behavior>
- YYYY-MM-DD — <one-line context>
Fingerprint Conventions
Format: <component>:<short-kebab-slug>
Examples:
kb-librarian:wrong-folder-routinglead-agent:skipped-fast-path-checksafe-commit:missed-secret-in-diffpaper-reader:hallucinated-citationkb-update:not-invoked-proactively
Pick the slug to be specific enough that genuinely different root causes get different fingerprints, but general enough that the same root cause maps to one entry. When unsure, pick the broader slug — over-grouping surfaces issues sooner; an over-grouped entry can always be split later when the fix is designed.
Three-Strike Prompt
When count reaches 3, surface the entry to the user with a message in roughly this form:
The failure <fingerprint> has now occurred 3 times:
<date 1> — <context 1><date 2> — <context 2><date 3> — <context 3>
Suspected root cause: <one-sentence hypothesis>
Recommended fix: <concrete suggestion — e.g. tighten skill instructions, add memory item, adjust agent description>
Options:
- (a) fix now — I'll draft the change
- (b) keep observing — leave entry open, no action
- (c) retire (won't fix) — accept as a known limitation
Do not silently apply a fix. Wait for the user's choice.
Retiring an Entry
When the user confirms a fix has been deployed (either via this skill's three-strike prompt, or out of band):
- Set
status: retired
- Add a
fix: field describing what changed, the file paths affected (use repo-relative paths via the fetch-repo-path skill, e.g. paper_reading_repo/...), and the date
- Move the entry from
## Open to ## Retired at the bottom of the ledger, so the active list stays scannable
- Update the ledger frontmatter
updated: date
Retired entry shape:
### <fingerprint>
- **status**: retired
- **component**: <…>
- **summary**: <…>
- **first-seen**: YYYY-MM-DD
- **count**: N
- **occurrences**:
- YYYY-MM-DD — <context>
- …
- **fix**: YYYY-MM-DD — <what changed; file paths; commit/PR if any>
If the same fingerprint recurs after retirement, resurrect it: move the entry back to ## Open, set status: open, append the new occurrence, and note in the fix: field that the previous fix was insufficient. Do not start a fresh entry — the history matters.
Initial Ledger Template
If agents-failure.md does not yet exist, create it with:
---
title: Agent Failure Ledger
summary: Append-only ledger of unexpected agent / skill / hook behavior. Failure types observed three times trigger a root-cause fix prompt; fixed entries move to the Retired section. Maintained by the `document-agent-failure` skill.
status: active
updated: <YYYY-MM-DD>
---
# Agent Failure Ledger
Maintained by the `document-agent-failure` skill (`~/.claude/skills/document-agent-failure/`).
## Open
(no entries yet)
## Retired
(no entries yet)
Confirmation Output
After every ledger update, output a short confirmation in this shape:
Logged <fingerprint> (count: N, status: open). [If N==3: see prompt above.]
Keep it to one or two lines — the ledger itself is the durable record.
