PostToolUseFailure

PostToolUseFailure is a hook for Claude Code from sifxprime/kodelyth-ecc. Its token cost is not measured, scanned A, original, MIT.

A post-failure hook that runs a Node.js script after a tool call fails. It checks the health of external tool servers and may try to reconnect.

In plain words
What is it for?
Use it to monitor failed MCP tool calls, mark unavailable servers, and attempt reconnection.
Why use it?
It helps detect failed or unhealthy tool connections automatically, so the agent can recover without manual troubleshooting.

Hook for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

Runs only inside a plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else, and the catalogue could not identify which plugin ships it.

One of 8 entries in hooks.json — they are configured in one file and arrive together.

Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for PostToolUseFailure

README.md
[![agentmods](https://agentmods.dev/badge/hooks/sifxprime/kodelyth-ecc/post-tool-use-failure.svg)](https://agentmods.dev/hooks/sifxprime/kodelyth-ecc/post-tool-use-failure)
Your own site
<a href="https://agentmods.dev/hooks/sifxprime/kodelyth-ecc/post-tool-use-failure"><img src="https://agentmods.dev/badge/hooks/sifxprime/kodelyth-ecc/post-tool-use-failure.svg" alt="Measured on agentmods" height="20"></a>
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

hooks/hooks.json · 15 lines

What it actually says

{
  "PostToolUseFailure": [
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hooks/run-with-flags.js\" \"post:mcp-health-check\" \"scripts/hooks/mcp-health-check.js\" \"standard,strict\""
        }
      ],
      "description": "Track failed MCP tool calls, mark unhealthy servers, and attempt reconnect",
      "id": "post:mcp-health-check"
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 8. Installing the file brings all of them; each is measured and scanned on its own page.

Changes

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.

  1. 2d ago First seen · 15 lines scan A 4256741b94ed

Subscribe to this mod's changes

PostToolUseFailure is a hook published in the GitHub repository sifxprime/kodelyth-ecc (11 stars, last pushed 3d ago), licensed MIT. 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. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.