The 'Frontend Tools' suggestion (setThemeColor) silently failed: the agent's
tools were static [set_proverbs, get_weather], and ag_ui_adk only injects the
run's forwarded client tools when the agent's tools include an AGUIToolset
placeholder (swapped for a ClientProxyToolset wired to input.tools). Without it,
gemini-2.5-flash never sees setThemeColor and declines ('I can only help with
proverbs or the weather'). Added AGUIToolset() to expose forwarded frontend tools.
Verified live via the identical change in examples/integrations/adk-angular
(same agent main.py + ag_ui_adk): 'Set the theme to green' now recolors the
panel; previously refused. No prompt change needed.
Benjamin Taylor