What
Plugins can add a tool.check hook. A hook is a piece of code that runs at a set moment, and this one runs before Claude uses a tool and can give a verdict on whether the tool may run. When the tool requires you to interact with it, Claude Code now keeps its own decision and holds back the hook's verdict.
Previously, the hook's verdict was held back only for MCP tool calls in remote sessions. MCP tools come from outside programs connected to Claude Code.
Why
A plugin can no longer approve a tool on your behalf when that tool is meant to wait for you.
Names in the bundletool.check
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on React to events with a mod touched a line naming tool.check after this was published.
To see the tool calls that the API ran itself during the request, such as calls to the [advisor tool](/docs/en/advisor), read `result.serverToolUses`. Claude Code doesn't run these calls, so no `tool.call` or `tool.check` hook fires for th…plugins/mods/events see the edit
Confirmed since
Anthropic's documentation has since written up tool.check, on React to events with a mod.
At `tool.check` and `plugin.register`, a refusal returned after `next` resolved still holds, so return it without testing `next.called`:plugins/mods/events see the edit
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up tool.check, on React to events with a mod.
Anthropic's release notes agree
Fixed a plugin's tool.check hook answering allow running a tool that requires your answer (a question, a plan approval) without showing its…