5 MCP Tool-Call Traps Every AI Agent Dev Should Avoid

Most AI Agent failures aren't about model intelligence—they're about broken MCP tool-call design. Vague tool descriptions confuse even GPT-5.5 and Claude Opus 4.8. Loose schemas make Gemini 3 hallucinate parameters. Missing retry logic means one network hiccup kills the whole pipeline. This post breaks down 5 high-frequency failure patterns with concrete fixes for each. The root causes apply regardless of which model you use. And if you're debugging agents across multiple models, XycAi gives you one API to access 200+ models—so switching and comparing is painless.