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Response from ADK Triaging Agent

Hello @nileshpatil6, thank you for creating this PR!

Could you please include a testing plan section in your PR to describe how you tested your changes? This will help reviewers to review your PR more efficiently. Thanks!

Testing Plan

Manual verification:

import json
from google.adk.telemetry.tracing import _safe_json_serialize

# Test 1: Circular reference (previously raised ValueError)
circular = {}
circular['self'] = circular
assert _safe_json_serialize(circular) == '<not serializable>'

# Test 2: Deeply nested structure (previously raised RecursionError)
deep = {}
node = deep
for _ in range(1000):
    node['child'] = {}
    node = node['child']
result = _safe_json_serialize(deep)
assert result == '<not serializable>'

# Test 3: Normal objects still serialize correctly
assert _safe_json_serialize({'key': 'value'}) == '{"key": "value"}'

print('All tests passed')

Before fix: _safe_json_serialize with a circular reference raises ValueError: Circular reference detected, which propagates out of the finally block and crashes tool execution.

After fix: Returns '<not serializable>' gracefully for all failure modes.

Hi @nileshpatil6 , Thank you for your contribution through this pull request! This PR has merge conflicts that require changes from your end. Could you please rebase your branch with the latest main branch to address these? Once this is complete, please let us know so we can proceed with the review.

Rebased on latest main. I noticed upstream already included ValueError in the except clause -- our change now only adds RecursionError to guard against deeply nested structures causing recursion during serialization. Please proceed with review when you get a chance.