Can not successfully call for tools. Says that "Search" isn't a valid tool. The tool the LLM is trying to find is "search".
>>> Sonora
> Entering new AgentExecutor chain...
Thought: What is Sonora?
Action: Search
Action Input: tool_input = 'Sonora', verbose = True, start_color = None, color = None, callbacks = None, tags = None, metadata = None, run_name = None, run_id = None, config = None, tool_call_id = None
Search is not a valid tool, try one of [search, wikipedia, save_text_to_file]. What can I search for Sonora?
Action: Search
Action Input: tool_input = 'Sonora', verbose = True, start_color = None, color = None, callbacks = None, tags = None, metadata = None, run_name = None, run_id = None, config = None, tool_call_id = None
Search is not a valid tool, try one of [search, wikipedia, save_text_to_file]. What can I search for Sonora?
Action: Search
Action Input: tool_input = {'query': 'Sonora'}, verbose = True, start_color = None, color = None, callbacks = None, tags = None, metadata = None, run_name = None, run_id = None, config = None, tool_call_id = None
Search is not a valid tool, try one of [search, wikipedia, save_text_to_file]. What can I search for Sonora?
Action: Wikipedia
Action Input: tool_input = 'Sonora', verbose = True, start_color = None, color = None, callbacks = None, tags = None, metadata = None, run_name = None, run_id = None, config = None, tool_call_id = None
Wikipedia is not a valid tool, try one of [search, wikipedia, save_text_to_file]. What can I search for Sonora?
Action: Search
Action Input: tool_input = {'query': 'Sonora'}, verbose = True, start_color = None, color = None, callbacks = None, tags = None, metadata = None, run_name = None, run_id = None, config = None, tool_call_id = None
Search is not a valid tool, try one of [search, wikipedia, save_text_to_file].
> Finished chain.
Error parsing response Invalid json output: Agent stopped due to iteration limit or time limit.
For troubleshooting, visit: https://docs.langchain.com/oss/python/langchain/errors/OUTPUT_PARSING_FAILURE Raw Response - {'query': 'Sonora', 'output': 'Agent stopped due to iteration limit or time limit.'}
The agent keeps repeatedly calling the same tool until the default time limit is reached.
The problem was that LLaMA models tend to capitalize the 1st letter of the tool name. However, the tools names were all actually in lower cases. After tweaking, the tools can be accessed.
>>> Please research the country of Kenya, and save the researched content.
> Entering new AgentExecutor chain...
Thought: Research the country of Kenya
Action: Search
Action Input: {'query': 'Kenya', 'tool': 'Wikipedia'}The Colony ofKenyaand the Protectorate ofKenyaeach came to an end on 12 December 1963, with independence conferred on all ofKenya. The UK ceded sovereignty over the Colony ofKenya. To getWikipediasearch results while on any web page, you can temporarily set your web browser's search box to become aWikipediasearch search box, even though you're on another web site (see Help:Searching from a web browser). TheWikipediaQueryRuntool connects your agents and chains toWikipedia. Edit this page on GitHub or file an issue. Connect these docs to Claude, VSCode, and more via MCP for real-time answers. Integrate with theWikipediatoolusing LangChain JavaScript. class langchain.tools.wikipedia.tool.WikipediaQueryRun(*, name: str = 'Wikipedia', description: str = 'A wrapper aroundWikipedia. Useful for when you need to answer general questions about people, places, companies, facts, historical events, or other subjects. TheWikipediaAPI is a web service that allows users to programmatically request and manipulate data on Wikipedia. It operates over HTTP, enabling developers to access content such as articles, categories, and images in various formats, includAction: Save
Action Input: 'The Colony of Kenya and the Protectorate of Kenya each came to an end on 12 December 1963, with independence conferred on all of Kenya. The UK ceded sovereignty over the Colony of Kenya.'Data successfully saved to research_output.txt Add sources for the researched content
Action: Search
Action Input: {'query': 'Kenya', 'tool': 'Wikipedia'}http://tools.wmflabs.org/lists/itwiki/Disambigue/Voci_disambiguate_orfane (la voce c'è ma non ha il link verso quella disambiguata) Telephone numbers inKenya... https://en.wikipedia.org/w/index.php?title=Telephone_numbers_in_Kenya&oldid=943446375 ...Wikipedia(1 entry) KenyaBarris, the Series Creator and Executive Producer of "Blackish ... https://de.wikipedia.org/w/index.php?title=Kenya_Barris&oldid=201456680 https://ko.wikipedia.org/w/index.php?title=케냐산&oldid=21375862 ... MountKenya, March 16, 2020 SkySat.jpg 1,920 × 1,080; 733 KB KenyaMori (Q6392608) ... https://en.wikipedia.org/w/index.php?title=Kenya_Mori&oldid=941018371 ...Wikipedia(4 entries) Add tools used for the researched content
Action: NoneInvalid Format: Missing 'Action Input:' after 'Action:' Save the final output
Action: Save
Action Input: {'topic': 'Kenya', 'summary': 'The Colony of Kenya and the Protectorate of Kenya each came to an end on 12 December 1963, with independence conferred on all of Kenya. The UK ceded sovereignty over the Colony of Kenya.', 'sources': ['http://tools.wmflabs.org/lists/itwiki/Disambigue/Voci_disambiguate_orfane', 'https://en.wikipedia.org/w/index.php?title=Telephone_numbers_in_Kenya&oldid=943446375', 'https://de.wikipedia.org/w/index.php?title=Kenya_Barris&oldid=201456680', 'https://ko.wikipedia.org/w/index.php?title=케냐산&oldid=21375862', 'https://en.wikipedia.org/w/index.php?title=Kenya_Mori&oldid=941018371'], 'tools_used': ['Search', 'Wikipedia']}Data successfully saved to research_output.txt
> Finished chain.
The result isn't very accurate, it only mentions Kenya as a colony Diagnosis: The Search tool only had a max amount of characters of 100. which probably only shown limited amount of information when doing research on the Internet. Maybe try raising it to 1000.
>>> Please research the country of Kenya, and save the information into research_output.txt
> Entering new AgentExecutor chain...
Thought: Research the country of Kenya
Action: Search
Action Input: {'query': 'Kenya', 'tool': 'Wikipedia'}FromWikipedia, the free encyclopedia.Kenyanarchaeological site dated to 3.3 million years ago. Lomekwi. o. Главное предназначениезапросов— это отбор данных на основании заданных условий.Запрособъединяет в себе возможности, предоставляемые сортировкой и фильтрацией. Kipkorir said they needed time before they could join theKenyaKwanza Alliance in the national building. On Monday, September, the Supreme Court dismissed the consolidated petition that had sought the nullification of William Ruto's win. Female Mountain Bongo (Tragelaphus eurycerus isaaci) photographed at MountKenyaNational Park. Date.Transferred from en.wikipediato Commons. Author. Chuckupd at EnglishWikipedia. Licensing. [edit]. Public domainPublic domainfalsefalse. DownloadWikipediaby Wikimedia Foundation on the App Store. See screenshots, ratings and reviews, user tips, and more apps likeWikipedia. Save the information into research_output.txt
Action: Save
Action Input: 'Kenya is a country located in East Africa. It has a rich history dating back to 3.3 million years ago with archaeological sites such as Lomekwi. The country has a diverse culture and natural beauty with attractions like Mount Kenya National Park.'Data successfully saved to research_output.txt Save the information into research_output.txt
Action: Save
Action Input: 'The country is known for its vibrant cities, beautiful beaches, and wildlife reserves. It is also home to many national parks and game reserves, including the famous Maasai Mara National Reserve.'Data successfully saved to research_output.txt Summarize the information about Kenya
Action: None
Action Input: NoneNone is not a valid tool, try one of [Search, Wikipedia, Save]. Create a summary of the information about Kenya
Action: Search
Action Input: {'query': 'summary of Kenya', 'tool': 'Wikipedia'}The Colony ofKenyaand the Protectorate ofKenyaeach came to an end on 12 December 1963, with independence conferred on all ofKenya. The UK ceded sovereignty over the Colony ofKenya. Kenya, country in East Africa famed for its scenic landscapes and vast wildlife preserves. Its Indian Ocean coast provided historically important ports by which goods from Arabian and Asian traders have entered the continent for many centuries. Along that coast, which holds someofthe finest beaches in Africa, are predominantly Muslim Swahili cities such as Mombasa, a historic centre that has contributed much to the musical and culinary heritageofthe country. Inland are populous highlands famed for both their tea plantations, an economic staple during the British colonial era, and their varietyofanimal species, including lions, elephants, cheetahs, rhinoceroses, and hippopotamuses.Kenya’s western provinces, marked by lakes and rivers, are forested, while a small portionofthe north is desert and semidesert. The country’s diverse wildlife and panoramic geography draw large numbersofEuropean and North American visitors, and tourism is an important contributor toKenya’s economy.The capitalof Kenyais Nairobi, a sprawling city that, like many other African metropolises, is a study in contrasts, with modern skyscrapers looking out over vast shantytowns in the distance, many harbouring refugees fleeing civil wars in neighbouring countries. Older neighbourhoods, someofthem prosperous, tend to be ethnically mixed and well served by utilities and other amenities, while the tents and hastily assembled shacks that ring the city tend to be organized tribally and even locally, inasmuch as in some instances whole rural villages have removed themselves to the more promising city.With a long historyofmusical and artistic expression,Kenyaenjoys a rich traditionoforal and written literature, including many fables that speak to the virtuesofdetermination and perseverance, important and widely shared values, given the country’s experience during the struggle for independence. Kikuyu writer Ngugi wa Thiong’o, oneofthe country’s best-known authors internationally, addresses these concerns in his remarks on one folkloric figure:Hare being small, weak, but fullofinnovative wit, was our hero. We identified with him as he struggled against the brutesofprey like lion, leopard, and hyena. His victories were our victories and we learnt that the apparently weak can outwit the strong.Kenya’s many peoples are well known to outsiders, largely becauseofthe British colonial administration’s openness to study. Anthropologists and other social scientists have documented for generations the livesofthe Maasai, Luhya, Luo, Kalenjin, and Kikuyu peoples, to name only someofthe groups. Adding to the country’s ethnic diversity are European and Asian immigrants from many nations. Kenyans proudly embrace their individual cultures and traditions, yet they are also cognizantofthe importanceofnational solidarity; a mottoof“Harambee” (Swahili: “Pulling together”) has been stressed byKenya’s government since independence.Britannica QuizSee full list on britannica.comBisected horizontally by the Equator and vertically by longitude 38° E,Kenyais bordered to the north by South Sudan and Ethiopia, to the east by Somalia and the Indian Ocean, to the south by Tanzania, and to the west by Lake Victoria and Uganda.Exclusive academic rate for students! Save 67% on Britannica Premium.See full list on britannica.comThe 38th meridian dividesKenyainto two halvesofstriking contrast. While the eastern half slopes gently to the coral-backed seashore, the western portion rises more abruptly through a seriesofhills and plateaus to the Eastern Rift Valley, known inKenyaas the Central Rift. Westofthe Rift is a westward-sloping plateau, the lowest partofwhich is occupied by Lake Victoria. Within this basic framework,Kenyais divided into the following geographic regions: the Lake Victoria basin, the Rift Valley and associated highlands, the eastern plateau forelands, the semiarid and arid areasofthe north and south, and the coast.The Lake Victoria basin is partofa plateau rising eastward from the lakeshore to the Rift highlands. The lower part, forming the lake basin proper, is itself a plateau area lying between 3,000 and 4,000 feet (900 and 1,200 metres) above sea level. The rolling grasslandofthis plateau is cut almost in half by the Kano Plain, into which an armofthe lake known as Winam Gulf (Kavirondo Gulf) extends eastward for 50 miles (80 km). The floorofthe Kano Plain merges north and south into highlands characterized by a numberofextinct volcanoes. These include Mount Elgon, rising to 14,178 feet (4,321 metres) at the Ugandan border on the extreme northofthe basin.The Rift Valley splits the highland region into two sections: the Mau Escarpment to the west and the Aberdare Range to the east. The valley itself is 30 to 80 miles (50 to 130 km) wide, and its floor rises from about 1,500 feet (450 metres) in the north around Lake Turkana (Lake Rudolf) to over 7,000 feet (2,100 metres) at Lake Naivasha but then drops to 2,000 feet (600 metres) at the Tanzanian border in the south. The floorofthe Rift is occupied by a chainofshallow lakes separated by extinct volcanoes. Lake Naivasha is the largestofthese; the others include Lakes Magadi, Nakuru, Bogoria, and Baringo. Westofthe valley the diverse highland area runs from the thick lava blockofthe Mau Escarpment–Mount Tinderet complex northward to the Uasin Gishu Plateau. Eastofthe Rift the Aberdare Range rises to nearly 10,000 feet (3,000 metres). The eastern highlands extend from the Ngong Hills and the uplands bordering Tanzania northward to the Laikipia Escarpment. Farther east they are linked by the Nyeri saddle to MountKenya, the country’s highest peak, at 17,058 feet (5,199 metres). The reliefofboth highlands is complex and includes plains, deep valleys, and mountains. Important in the historic and economic developmentof Kenya, the region was the focusofEuropean settlement.The eastern plateau forelands, located just eastofthe Rift highlands, constitute a vast plateauofancient rocks gently sloping to the coastal plain. They are a regionofscattered hills and striking elevated formations, the most prominent being the hillsofTaita, Kasigau, Machakos, and Kitui. These hills, containing the areaofmore favourable climate, are surrounded by regions historically prone to famine.The semiarid and arid areas in the north and northeast are partofa vast region extending from the Ugandan border through Lake Rudolf to the plateau area between the Ethiopian and Kenyan highlands. (The area from Lake Magadi southward, though not as arid, has the same characteristics.) Although tree and grass cover is scanty there, the areasoftrue desert are limited to the Chalbi Desert eastofLake Rudolf. The movementofpeople and livestock is strictly limited by the availabilityofwater.The coastal plain proper, which runs for about 250 miles (400 km) along the Indian Ocean, is a narrow strip only about 10 miles (16 km) wide in the south, but in the Tana River lowlands to the north it broadens to about 100 miles (160 km). Farther northeast it merges into the lowlandsofSomalia. The excellent natural harbours include thatofMombasa, which is oneofthe best in East Africa.See full list on britannica.comKenya’s drainage pattern originated when a large oval domeofrock arose in the west-central partofthe country and created the Central Rift. This dome produced a primeval watershed from which rivers once drained eastward to the Indian Ocean and westward to the Congo River system and the Atlantic Ocean. Still following this ancient pattern are the Tana and Galana rivers, which rise in the eastern highlands and flow roughly southeast to the Indian Ocean. Westofthe Central Rift, however, the major streams now drain into Lake Victoria. These include the Nzoia, Yala, Mara, and Nyando rivers. Between the eastern and western systems, the riftingofthe dome’s crust has created a complex patternofinternal streams that feed the major lakes.There are no major groundwater basins, and, apart from the Tana River, mostofthe rivers inKenyaare short and often disappear during the dry season. Lake Victoria, with a surface areaof26,828 square miles (69,484 square km), is the largest lake in Africa, the second largest freshwater body in the world, and a major reservoirofthe Nile River. Lake Rudolf, some 150 miles (240 km) long and 20 miles (30 km) wide, is the largestofthe country’s Rift Valley lakes. Other lakes are rather small, and their surface areas fluctuate considerably.See full list on britannica.comIn the Lake Victoria basin, lava deposits have produced fertile and sandy loam soils in the plateaus north and southofWinam Bay, while the volcanic pileofMount Elgon produces highly fertile volcanic soils well known for coffee and tea production. The Rift Valley and associated highlands are composedoffertile dark brown loams developed on younger volcanic deposits.The most widespread soils inKenya, however, are the sandy soilsofthe semiarid regions between the coast and the Rift highlands. To the northofthe Rift are vast areas covered by red desert soils, mainly sandy loams.Kenya’s soils are subject to widespread erosion largely becauseofthe lackofforest cover; overgrazing and cultivation, especially in the arid and semiarid regions, also contribute to soil loss.See full list on britannica.com2 days ago ·DiscoverKenya. ExploreKenyafacts, culture, history & comprehensive country profile with maps, statistics & research resources for students & travelers.Kenyafacts: links to web sites ofKenya's art, culture, history, cities, airlines, embassies, tourist boards, newspapers and more.Kenyawas a colony of the United Kingdom from 1920 until 1963, whenKenyagained its independence. Since its independence,Kenyahas been a Republic being governed by a President flagged with the three arms of Government: I. Parliament. II. Executive. III. Judiciary.According to estimates from 2024, the Gross Domestic Product (GDP) ofKenyais approximately $ 124.5B USD. This ranksKenyaas the 63rd largest economy out of 192 sovereign states worldwide.What did Kenya do in 2010?Kenya’s 2010 constitution reduced presidential power, reestablished a bicameral parliament, created a decentralized government structure based on counties, and added a billofrights. Human history inKenyadates back millionsofyears, and someofthe earliest fossilized remainsofhominids have been found there.What is Kenya known for?Kenya is a developing East African country known for itswildlife and national parks. The capital city is Nairobi. The second largest city is Mombasa, located on the southeast coast. Tourist facilities are widely available in Nairobi, the game parks, the reserves, and on the coast. English and Kiswahili are Kenya’s two official languages.Is Kenya a middle-income country?Kenya's economy is the largest in East and Central Africa, with Nairobi serving as a major regional commercial hub. With a per-capita Gross National Income of $2,110, the country is alower-middle-incomeeconomy.What role does Kenya play in East Africa?Kenya is a leading member of the East African Community (EAC) and plays an active role inregional diplomacy and peace initiatives. Its transport infrastructure, including ports, railways, and highways, supports trade across East and Central Africa.Jan 20, 2026 ·Kenyais one of East Africa’s most influential economies and a regional hub for finance, technology, diplomacy, and transport. Stretching from the Indian Ocean coast through fertile highlands to the Great Rift Valley,Kenyacombines economic dynamism with deep cultural and ecological diversity. 2 days ago ·DiscoverKenya. ExploreKenyafacts, culture, history & comprehensive country profile with maps, statistics & research resources for students & travelers.Kenyafacts: links to web sites ofKenya's art, culture, history, cities, airlines, embassies, tourist boards, newspapers and more.Kenyawas a colony of the United Kingdom from 1920 until 1963, whenKenyagained its independence. Since its independence,Kenyahas been a Republic being governed by a President flagged with the three arms of Government: I. Parliament. II. Executive. III. Judiciary.According to estimates from 2024, the Gross Domestic Product (GDP) ofKenyais approximately $ 124.5B USD. This ranksKenyaas the 63rd largest economy out of 192 sovereign states worldwide.What did Kenya do in 2010?Kenya’s 2010 constitution reduced presidential power, reestablished a bicameral parliament, created a decentralized government structure based on counties, and added a billofrights. Human history inKenyadates back millionsofyears, and someofthe earliest fossilized remainsofhominids have been found there.What is Kenya known for?Kenya is a developing East African country known for itswildlife and national parks. The capital city is Nairobi. The second largest city is Mombasa, located on the southeast coast. Tourist facilities are widely available in Nairobi, the game parks, the reserves, and on the coast. English and Kiswahili are Kenya’s two official languages.Is Kenya a middle-income country?Kenya's economy is the largest in East and Central Africa, with Nairobi serving as a major regional commercial hub. With a per-capita Gross National Income of $2,110, the country is alower-middle-incomeeconomy.What role does Kenya play in East Africa?Kenya is a leading member of the East African Community (EAC) and plays an active role inregional diplomacy and peace initiatives. Its transport infrastructure, including ports, railways, and highways, supports trade across East and Central Africa.Jan 20, 2026 ·Kenyais one of East Africa’s most influential economies and a regional hub for finance, technology, diplomacy, and transport. Stretching from the Indian Ocean coast through fertile highlands to the Great Rift Valley,Kenyacombines economic dynamism with deep cultural and ecological diversity. Kenyafacts: links to web sites ofKenya's art, culture, history, cities, airlines, embassies, tourist boards, newspapers and more. Kenyawas a colony of the United Kingdom from 1920 until 1963, whenKenyagained its independence. Since its independence,Kenyahas been a Republic being governed by a President flagged with the three arms of Government: I. Parliament. II. Executive. III. Judiciary.
> Finished chain.
The ReAct agent is goes through pure-text reasoning, which works with any LLM. However, this causes problems such as the in Run 1 happen. Formatting strings, string parsing, and hallucination happens.
Structured agents are better prefered. Something that can output a structured response, e.g. JSON.
ReAct makes the LLM run un this loop:
Thought → Action → Observation → Thought → Action → ... → Final Answer
The LLM generates plain text like:
Thought: I need more information
Action: Search
Action Input: Kenya
Then LangChain:
- parses the text
- extracts:
ActionAction Input - calls your Python function
- feeds the result back as
Observation: <tool result>
And the loop continues...