Inconsistent promp when calling LLMGraphTransformer with ChatOllama using from langchain_ollama import ChatOllama

[csaiedu]

Checked other resources

• I added a very descriptive title to this issue.
• I searched the LangChain documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

Example Code

from langchain_experimental.graph_transformers import LLMGraphTransformer
from langchain_community.chat_models import ChatOllama
from langchain_core.documents import Document
from langchain_community.graphs.graph_document import GraphDocument

llm = ChatOllama(model=local model)
llm_transformer = LLMGraphTransformer(
    llm=llm,
)
doc= Document(page_content="The dog has a ball which is red")
graph=llm_transformer.convert_to_graph_documents([doc])
print(graph)

from langchain_ollama import ChatOllama

llm = ChatOllama(model=local model)
llm_transformer = LLMGraphTransformer(
    llm=llm,
)
doc= Document(page_content="The dog has a ball which is red")
graph=llm_transformer.convert_to_graph_documents([doc])
print(graph)

Error Message and Stack Trace (if applicable)

No response

Description

In this code example the outcome of of processing a simple text through LLMGraphTransformer changes if I replace the definition of ChatOllama from

from langchain_community.chat_models import ChatOllama

to

from langchain_ollama import ChatOllama

Output :
from langchain_community.chat_models import ChatOllama
page_content='The dog has a ball which is red'
[GraphDocument(nodes=[Node(id='dog', type='Animal', properties={}), Node(id='ball', type='Object', properties={})], relationships=[Relationship(source=Node(id='dog', type='Animal', properties={}), target=Node(id='ball', type='Object', properties={}), type='HAS_OBJECT', properties={})], source=Document(metadata={}, page_content='The dog has a ball which is red'))]

from langchain_ollama import ChatOllama
page_content='The dog has a ball which is red'
[GraphDocument(nodes=[Node(id='John Doe', properties={}), Node(id='Red Ball', properties={})], relationships=[], source=Document(metadata={}, page_content='The dog has a ball which is red'))]

System Info

langchain_core '0.3.1'
langchain_community '0.3.0'
langchain_experimental '0.3.0'
langchain_ollama '0.2.0'

[csaiedu]

It seems to be related by looking at ollama Debug logs, to an incorrect prompt syntax
"[INST] You are a top-tier algorithm designed for extracting ..."
becomes
prompt="[AVAILABLE_TOOLS] [{"type":"function","function":{"name":"DynamicGraph","description":"Represents a graph document consisting of nodes and relationships.","parameters":{"type":"object","required":["nodes","relationships"],"properties":{"nodes":{"type":"","description":"List of nodes"},"relationships":{"type":"","description":"List of relationships"}}}}}][/AVAILABLE_TOOLS][INST] # Knowledge Graph Instructions for GPT-4...

There might have been changed in chatollama to accomodate for function calling ("With Structured Output") that are not working correctly and referecing instruction for GPT4