An agent is tasked with updating all references to a deprecated function calculateTax() to use its replacement calculateTaxV2(). In 8% of cases, the agent updates the function call but fails to update the import statement that imports calculateTax, causing a compilation error. The tool used to make the update (a find-and-replace tool) reports success, and the agent's reasoning correctly identifies that both the function call and import must be updated. However, the agent calls the tool only for the function call, not for the import. Which error class does this represent?
Select an answer to reveal the explanation.
Short Explanation and Infographic
The agent knows what needs to be done — it even says so in its reasoning. But knowing and doing are two different things. This is not a reasoning failure (the logic is correct) or a tool failure (the tool works fine) or a context failure (the agent mentions the import). It's a translation failure: the bridge between 'I know I need to do X and Y' and 'I will now call the tool for X and then Y' is broken.
Full explanation below image
Full Explanation
Error classification in agentic systems requires distinguishing between where in the pipeline the failure originates. The key evidence in this scenario:
- The agent's reasoning correctly identifies that both the function call and the import statement must be updated → reasoning is correct - The tool reports success when called → tool is functioning correctly - The agent's context includes the import section (it mentions it in reasoning) → context is complete - The agent calls the tool for the function call but not for the import → the failure is in translating complete reasoning into a complete set of tool calls
This is a reasoning-to-action gap: the agent produces a correct analysis but generates an incomplete action sequence. This error class is distinct from the three more commonly discussed classes:
- Reasoning errors: The agent draws incorrect conclusions from available information - Tool errors: The tool returns incorrect, incomplete, or error responses - Context errors: The agent lacks necessary information to make correct decisions
The reasoning-to-action gap is particularly insidious because it appears correct at every observable layer except the final action sequence. Traces will show correct reasoning and successful tool calls — only comparison of the planned actions against the executed actions reveals the gap.
The fix is typically to improve the agent's action generation prompt, require the agent to enumerate all planned tool calls before executing any of them (structured plan output), and validate that the action sequence covers all items identified in the reasoning phase before execution begins. Option A is incorrect — the agent's reasoning explicitly identifies the import update. Option B is incorrect — the tool successfully performs the update when called; it is simply not called for the import. Option C is incorrect — the import section is present in the agent's reasoning context. The discriminating fact is that the reasoning was correct but incomplete tool call coverage.