Incorrect error message in multiple tool calls assertion

[krystianMoras]

instructor/instructor/function_calls.py

Line 251 in 8954095

len(message.tool_calls or []) == 1

This assertion fails if for some reason LLM does not respond e.g. connection issues. If message.tool_calls is None it does not mean that an LLM output had multiple tools.

None or []

Outputs:

[]

This means that:

len([]) == 1

False

Please change the assertion error message to sth else as this is confusing.

[jxnl]

can take a pr for this