Update langgraph_agent.py

langgraph_agent.py

@@ -8,31 +8,37 @@ from langchain_community.document_loaders import WikipediaLoader, ArxivLoader
 from langchain_core.messages import SystemMessage, HumanMessage
 from langchain_core.tools import tool
 
-#tools
 @tool
 def multiply(a: int, b: int) -> int:
+    """Multiply two integers."""
     return a * b
 
 @tool
 def add(a: int, b: int) -> int:
+    """Add two integers."""
     return a + b
 
 @tool
 def subtract(a: int, b: int) -> int:
+    """Subtract the second integer from the first."""
     return a - b
 
 @tool
 def divide(a: int, b: int) -> float:
+    """Divide first integer by second; error if divisor is zero."""
     if b == 0:
         raise ValueError("Cannot divide by zero.")
     return a / b
 
 @tool
 def modulus(a: int, b: int) -> int:
+    """Return the remainder of dividing first integer by second."""
     return a % b
 
+
 @tool
 def wiki_search(query: str) -> dict:
+    """Search Wikipedia for a query and return up to 2 documents."""
     docs = WikipediaLoader(query=query, load_max_docs=2).load()
     formatted = "\n\n---\n\n".join(
         f'<Document source="{d.metadata["source"]}"/>\n{d.page_content}'
@@ -42,6 +48,7 @@ def wiki_search(query: str) -> dict:
 
 @tool
 def web_search(query: str) -> dict:
+    """Perform a web search (via Tavily) and return up to 3 results."""
     docs = TavilySearchResults(max_results=3).invoke(query=query)
     formatted = "\n\n---\n\n".join(
         f'<Document source="{d.metadata["source"]}"/>\n{d.page_content}'
@@ -51,6 +58,7 @@ def web_search(query: str) -> dict:
 
 @tool
 def arvix_search(query: str) -> dict:
+    """Search arXiv for a query and return up to 3 paper excerpts."""
     docs = ArxivLoader(query=query, load_max_docs=3).load()
     formatted = "\n\n---\n\n".join(
         f'<Document source="{d.metadata["source"]}"/>\n{d.page_content[:1000]}'
@@ -58,24 +66,21 @@ def arvix_search(query: str) -> dict:
     )
     return {"arvix_results": formatted}
 
-
 OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
 HF_SPACE_TOKEN = os.getenv("HF_SPACE_TOKEN")
 
-# ───────────────────────────────────────────────────────────────────────────────
-# 4) Assemble tool list
+
 tools = [
     multiply, add, subtract, divide, modulus,
     wiki_search, web_search, arvix_search,
 ]
 
-# ───────────────────────────────────────────────────────────────────────────────
-# 5) Load your system prompt
+
 with open("system_prompt.txt", "r", encoding="utf-8") as f:
     system_prompt = f.read()
 sys_msg = SystemMessage(content=system_prompt)
 
-# ───────────────────────────────────────────────────────────────────────────────
+
 def build_graph(provider: str = "openai"):
     """Build the LangGraph agent with chosen LLM (default: OpenAI)."""
     if provider == "openai":