{"title":"Tool Integrity: Preventing Hallucinated Function Calls","region":"Global","category":"Reliability","description":"Five controls to ensure agents only call tools that actually exist.","lastUpdated":"2026-02-22","steps":["Inject a current tool manifest and forbid calls outside the list.","Normalize common hallucinated tool names to real function names.","Validate tool calls against a local registry before execution.","Require a safe fallback response when a needed tool is unavailable.","Limit the toolset to only what the current task phase requires."],"url":"https://checklist.day/agent-tool-call-verification"}