What
Failures validating --permission-prompt-tool now have fixed redacted variants for telemetry, so the reported error omits the tool name and the list of available MCP tools.
Evidence
Error: tool <redacted> (passed via --permission-prompt-tool) must be an MCP tool
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Names in the bundle--permission-prompt-tool
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.
Confirmed since
Anthropic's documentation has since written up --permission-prompt-tool, on Hooks reference.
The `AskUserQuestion` tool is the typical case: Claude wants to ask the user something, but there is no terminal to answer in. A `-p` run offers `AskUserQuestion` only when it has a [permission host](/docs/en/headless#turn-off-permission-p…hooks see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up --permission-prompt-tool, on Hooks reference.