Error type
Tool calls and arguments
8 guides: 0 fixed, 3 workaround, 2 open.
- LangGraphUnverified
"tool_use ids were found without tool_result blocks" on a saved thread
An agent with a database checkpointer fails on every new message in one thread with a tool_use/tool_result mismatch error.
Last checked#state#tool-calls3 steps → - LangGraphWorkaround
Agent repeats the same tool call until it hits the recursion limit
A prebuilt agent keeps calling tools step after step and only stops when GraphRecursionError is raised.
Last checked#loop#tool-calls5 steps → - n8nUnverified
AI Agent tools fail with 'schema must be type object, got None' after upgrading
After upgrading, the agent fails before calling any tool.
Last checked#regression#tool-calls3 steps → - browser-useUnverified
Browser agent keeps emitting empty actions until max steps
Sometimes the agent outputs an empty action every step until the step limit, even though it read the right data.
Last checked#schema#tool-calls3 steps → - LangGraphOpen
Cancelled async tool leaves history invalid even with handle_tool_errors=True
After a tool task is cancelled, the next model call fails with INVALID_CHAT_HISTORY.
Last checked#state#tool-calls3 steps → - CrewAIWorkaround
Every tool call arrives with empty arguments and fails validation
Each tool call fails with 'Field required ... input_value={}' and the agent repeats until max iterations.
Last checked#tool-calls#schema3 steps → - n8nOpen
One bad tool call ends the whole agent run
The run ends with 'Received tool input did not match expected schema' and the user gets nothing.
Last checked#tool-calls#schema3 steps → - ContinueWorkaround
Tool calls fail because arguments come back as XML-like text
In agent mode, tool calls break with empty arguments or list/index errors when using a self-hosted compatible endpoint.
Last checked#tool-calls#serving3 steps →