This reverts commit 65a46a5f32 (#38113)
That change made two edits that combine into a hard failure for SDK
users. It dropped the null-router guard in
_select_search_tool_from_router, so a missing router now yields an empty
search_tools list instead of returning early, and it turned the no-match
case in _select_search_tool_from_list from a debug-logged fallback into
a raised ValueError. It also added a call site in
async_pre_call_deployment_hook that invokes the selection purely for the
side effect of raising, discarding the return value
Used together, any SDK caller that sets search_tool_name and sends a web
search tool now raises "Configured search tool '<name>' was not found"
on every request. There is no way to satisfy the check off the proxy,
because search_tools is only ever populated from the proxy router, so
the SDK path cannot register one
tests/pass_through_unit_tests/test_websearch_interception_e2e.py caught
this, but #38113 only updated the handler unit tests, so the break
landed on staging
Reverting restores the previous behavior while we work out a fix that
keeps the stricter validation on the proxy path, where a silently
substituted search provider is the real problem worth rejecting, without
turning the SDK path into an unconditional error
201f60d19c