429 RESOURCE_EXHAUSTED Error When Using Grounding Tool

When using grounding web search with the gemini-2.5-flash model,
I repeatedly encounter 429 RESOURCE_EXHAUSTED errors after making approximately 5,000-6,000 requests per day.

No meaningful information could be found in the error details.

`google.genai.errors.ClientError: 429 RESOURCE_EXHAUSTED. {'error': {'code': 429, 'message': 'You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits.', 'status': 'RESOURCE_EXHAUSTED', 'details': [{'@type': 'type.googleapis.com/google.rpc.Help', 'links': [{'description': 'Learn more about Gemini API quotas', 'url': 'https://ai.google.dev/gemini-api/docs/rate-limits'}]}]}}`

Current API usage tier is tier3.