fix(core): ensure tool_call_count is never null

[mdrxy]

add truthiness check to guard against None

[codspeed-hq]

CodSpeed Performance Report

Merging #34431 will not alter performance

_{Comparing mdrxy/fix-null-tool-call-count (c4d76c0) with master (ed9bd6e)}

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

Summary

✅ 13 untouched
⏩ 21 skipped¹

Footnotes

1. 21 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩