Unclear Exactly which hook replies cause a fetch to be denied is not settled.
What
WebFetch is the tool Claude uses to read a web page. A PermissionRequest hook is your own script that runs when a tool call needs a permission decision, and it can approve the call. If such a hook approves a fetch but also attaches arguments WebFetch cannot check, Claude Code now denies the fetch. The message says nothing was fetched because the hook approved it with arguments WebFetch cannot check. This kind of approval is also never treated as one an automatic classifier could approve.
Why
It stops a hook from changing the address or the request on its way through without the permission check seeing what changed.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
Exactly which hook replies cause a fetch to be denied is not settled.