Thanks — I hear you: you’re hitting a

ValidationError

for

$schema

during

session.start()

when

update_tools

runs, and you suspect the Google plugin’s

to_fnc_ctx

isn’t stripping

$schema

from tool JSON schemas. I don’t have any documentation or notes that this is a known bug in the Google plugin’s schema sanitizer, and there’s no official guidance showing an automatic strip of

$schema

. To help narrow this down and give a concrete next step, could you share the following: 1. A minimal reproducible example (Python) that shows how you create the dynamic tool(s) and call

session.start()

/

update_tools

. 2. The exact tool definition (or one example) that includes the

$schema

key as passed into the plugin (redact any secrets). 3. The versions of

livekit-plugins-google

and

livekit-agents

(you mentioned

livekit-agents

v1.3.9; please confirm

livekit-plugins-google

exact version). While you gather that, a practical workaround you can try immediately: before passing dynamic tool definitions to

update_tools

, remove

$schema

from each tool’s JSON/schema object (e.g., pop the

$schema

key). If that prevents the ValidationError it indicates the sanitizer/validator is rejecting extra keys and confirms the immediate cause. Send the minimal example and tool payload and I’ll look at it and recommend the next fix or pinpoint whether this looks like a plugin bug. Sources: Tool definition and use | LiveKit docs