fix(llmobs): do no annotate self for automatic annotations with decorators (#15349)

## Description

Makes sure `self` is not decorated when using LLMObs decorators.

Closes #14849 

## Testing

Unit tests added

## Risks

Should not be a breaking change as although we run evaluations on input
values, they are not used as far as I know as part of monitors or
sampling rates for evaluations. If anything, it might help with
evaluations on spans that had `self` annotated previously as a result of
using decorators without manual annotation override.

Author: sabrenner

ddtrace/llmobs/decorators.py

@@ -6,6 +6,7 @@
 import sys
 from typing import Callable
 from typing import Optional
+from typing import OrderedDict
 
 from ddtrace.internal.logger import get_logger
 from ddtrace.llmobs import LLMObs
@@ -28,6 +29,10 @@ def _get_llmobs_span_options(name, model_name, func):
     return traced_model_name, span_name
 
 
+def _get_span_inputs(args: OrderedDict) -> dict:
+    return {arg: value for arg, value in args.items() if arg != "self"}
+
+
 async def yield_from_async_gen(func, span, args, kwargs):
     try:
         gen = func(*args, **kwargs)
@@ -176,7 +181,7 @@ def generator_wrapper(*args, **kwargs):
                     func_signature = signature(func)
                     bound_args = func_signature.bind_partial(*args, **kwargs)
                     if _automatic_io_annotation and bound_args.arguments:
-                        LLMObs.annotate(span=span, input_data=dict(bound_args.arguments))
+                        LLMObs.annotate(span=span, input_data=_get_span_inputs(bound_args.arguments))
                     return yield_from_async_gen(func, span, args, kwargs)
 
                 @wraps(func)
@@ -192,7 +197,7 @@ async def wrapper(*args, **kwargs):
                         func_signature = signature(func)
                         bound_args = func_signature.bind_partial(*args, **kwargs)
                         if _automatic_io_annotation and bound_args.arguments:
-                            LLMObs.annotate(span=span, input_data=dict(bound_args.arguments))
+                            LLMObs.annotate(span=span, input_data=_get_span_inputs(bound_args.arguments))
                         resp = await func(*args, **kwargs)
                         if (
                             _automatic_io_annotation
@@ -217,7 +222,7 @@ def generator_wrapper(*args, **kwargs):
                         func_signature = signature(func)
                         bound_args = func_signature.bind_partial(*args, **kwargs)
                         if _automatic_io_annotation and bound_args.arguments:
-                            LLMObs.annotate(span=span, input_data=dict(bound_args.arguments))
+                            LLMObs.annotate(span=span, input_data=_get_span_inputs(bound_args.arguments))
                         try:
                             yield from func(*args, **kwargs)
                         except (StopIteration, GeneratorExit):
@@ -242,7 +247,7 @@ def wrapper(*args, **kwargs):
                         func_signature = signature(func)
                         bound_args = func_signature.bind_partial(*args, **kwargs)
                         if _automatic_io_annotation and bound_args.arguments:
-                            LLMObs.annotate(span=span, input_data=dict(bound_args.arguments))
+                            LLMObs.annotate(span=span, input_data=_get_span_inputs(bound_args.arguments))
                         resp = func(*args, **kwargs)
                         if (
                             _automatic_io_annotation

releasenotes/notes/llmobs-no-annotate-self-9da3db98283403a7.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    LLM Observability: Resolves an issue where ``self`` was being annotated as an input parameter using LLM Observability function decorators.

tests/llmobs/test_llmobs_decorators.py

@@ -1,3 +1,5 @@
+import json
+
 import mock
 import pytest
 
@@ -828,3 +830,23 @@ def get_next_element(alist):
         error_message=span.get_tag("error.message"),
         error_stack=span.get_tag("error.stack"),
     )
+
+
+@pytest.mark.parametrize(
+    "decorator",
+    [task, tool, workflow, agent],
+    ids=["task", "tool", "workflow", "agent"],
+)
+def test_generator_for_class_does_not_annotate_self(llmobs, llmobs_events, decorator):
+    class TestClass:
+        @decorator
+        def add(self, a: int, b: int) -> int:
+            return a + b
+
+    test_class = TestClass()
+    test_class.add(1, 2)
+
+    assert len(llmobs_events) == 1
+
+    input_value = json.loads(llmobs_events[0]["meta"]["input"]["value"])
+    assert input_value == {"a": 1, "b": 2}