docs: Fix tracing setup documentation

- Replace stub documentation in docs/ref/tracing/setup.md with comprehensive content
- Add detailed function documentation for all setup functions
- Include practical examples and common setup patterns
- Add troubleshooting section for common setup issues
- Document environment variables and configuration options

Fixes incomplete reference documentation that was previously just a module reference.

Author: abdul-kabir-jawed

docs/ref/tracing/setup.md

@@ -1,3 +1,147 @@
-# `Setup`
+# Tracing Setup
 
-::: agents.tracing.setup
+The tracing setup module provides functions to configure and initialize tracing for OpenAI Agents.
+
+## Functions
+
+### `set_tracing_disabled(disabled: bool) -> None`
+
+Disables or enables tracing globally.
+
+```python
+from agents import set_tracing_disabled
+
+# Disable tracing globally
+set_tracing_disabled(True)
+
+# Re-enable tracing
+set_tracing_disabled(False)
+```
+
+### `set_tracing_export_api_key(api_key: str) -> None`
+
+Sets the API key used for exporting traces to OpenAI's backend.
+
+```python
+from agents import set_tracing_export_api_key
+
+# Set a specific API key for tracing
+set_tracing_export_api_key("sk-your-openai-api-key")
+```
+
+### `add_trace_processor(processor: TraceProcessor) -> None`
+
+Adds an additional trace processor to the existing processors.
+
+```python
+from agents import add_trace_processor
+from agents.tracing.processors import TraceProcessor
+
+class CustomTraceProcessor(TraceProcessor):
+    def process_trace(self, trace):
+        # Custom processing logic
+        print(f"Processing trace: {trace.trace_id}")
+
+# Add custom processor
+add_trace_processor(CustomTraceProcessor())
+```
+
+### `set_trace_processors(processors: list[TraceProcessor]) -> None`
+
+Replaces all existing trace processors with the provided list.
+
+```python
+from agents import set_trace_processors
+from agents.tracing.processors import BatchTraceProcessor, BackendSpanExporter
+
+# Replace with custom processors
+custom_processors = [
+    BatchTraceProcessor(BackendSpanExporter()),
+    CustomTraceProcessor()
+]
+set_trace_processors(custom_processors)
+```
+
+## Environment Variables
+
+### `OPENAI_AGENTS_DISABLE_TRACING`
+
+Set to `1` to disable tracing globally.
+
+```bash
+export OPENAI_AGENTS_DISABLE_TRACING=1
+```
+
+## Common Setup Patterns
+
+### Basic Setup with Custom API Key
+
+```python
+import os
+from agents import set_tracing_export_api_key, Agent, Runner
+
+# Set up tracing with custom API key
+tracing_api_key = os.environ.get("OPENAI_TRACING_API_KEY")
+if tracing_api_key:
+    set_tracing_export_api_key(tracing_api_key)
+
+agent = Agent(name="Assistant", instructions="You are helpful")
+result = await Runner.run(agent, "Hello world")
+```
+
+### Setup with Custom Processor
+
+```python
+from agents import add_trace_processor, Agent, Runner
+from agents.tracing.processors import TraceProcessor
+import json
+
+class LoggingTraceProcessor(TraceProcessor):
+    def process_trace(self, trace):
+        # Log trace to file
+        with open("traces.log", "a") as f:
+            f.write(json.dumps({
+                "trace_id": trace.trace_id,
+                "workflow_name": trace.workflow_name,
+                "timestamp": trace.started_at.isoformat()
+            }) + "\n")
+
+# Add logging processor
+add_trace_processor(LoggingTraceProcessor())
+
+agent = Agent(name="Assistant")
+result = await Runner.run(agent, "Test message")
+```
+
+### Disable Tracing for Specific Runs
+
+```python
+from agents import Agent, Runner, RunConfig
+
+agent = Agent(name="Assistant")
+
+# Disable tracing for this specific run
+result = await Runner.run(
+    agent, 
+    "Hello world",
+    run_config=RunConfig(tracing_disabled=True)
+)
+```
+
+## Troubleshooting
+
+### Common Issues
+
+1. **401 Unauthorized Error**: Make sure you have a valid OpenAI API key set
+2. **Tracing Not Working**: Check if `OPENAI_AGENTS_DISABLE_TRACING=1` is set
+3. **Custom Processors Not Receiving Data**: Ensure processors are added before running agents
+
+### Debug Mode
+
+Enable verbose logging to debug tracing issues:
+
+```python
+from agents import enable_verbose_stdout_logging
+
+enable_verbose_stdout_logging()
+```