Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add hooks/fatmo666/caushell/post-tool-use-failuregit clone --depth 1 https://github.com/fatmo666/CaushellGrade A, and why
PostToolUseFailure scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the commands this hook runs, not an audit. A hook is shell that executes on your machine at the event it names, which is why every command in it is printed with what was found.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
86% identical to PreToolUse — 4 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
{
"PostToolUseFailure": [
{
"matcher": "Bash",
"hooks": [
{
"type": "command",
"command": "${CLAUDE_PLUGIN_ROOT}/bin/caushell-claude-hook",
"args": [
"PostToolUseFailure"
]
}
]
}
]
}What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 16 lines scan A 82f1457e6842
PostToolUseFailure is a hook published in the GitHub repository fatmo666/Caushell (6 stars, last pushed 2d ago), licensed Apache-2.0. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it A with 0 findings. It is 86% identical to PreToolUse, differing in 4 lines, and is treated as a copy.
Other hooks, from other repositories
Notification
Runs when the agent sends a notification for idle_prompt tool calls, running afplay /System/Library/Sounds/Sosumi.aiff. From fredrikaverpil/dotfiles.
PostCompact
Runs after the context is compacted for manual and auto tool calls, executing run.py via python (2 commands). From ChanMeng666/echook.
PermissionDenied
Runs on the PermissionDenied event, executing run.py via python. From ChanMeng666/echook.
Elicitation
Runs when the agent asks you a question, executing run.py via python. From ChanMeng666/echook.
ElicitationResult
Runs on the ElicitationResult event, executing run.py via python. From ChanMeng666/echook.
PreToolUse
Runs before the agent uses a tool for Bash, Write, Edit, NotebookEdit and Agent tool calls, executing validate-bash.sh, guard-files.sh and guard-agents.sh (3 commands). From MokeyBytes/claude-baseline.