UTF-8 encoding issues in tool calling params with GPT-4o model

[jackien1]

Describe the bug

The gpt-4o agent encodes the str argument to a tool call in latin-1 encoding instead of utf-8 whenever smart / curly quotes are involved. If another tool uses the same text, the memory of the argument as latin-1 causes subsequent double encoding issues.

Debug information

• Agents SDK version: v0.0.6
• Python version Python 3.12

Repro steps

Have a gpt-4o agent use a tool that writes a script and uses any unicode characters like smart / curly quotes.

Expected behavior

String parameters should be in utf-8 encoding unless I fundamentally misunderstand tool calling.

Alright, now let�s break it down! instead of "Alright, now let's break it down!"

[jackien1]

Closing this issue since no one else seems to be getting it and gpt-4.1 clears.