Tool & Error Anti-Patterns

Most agent failures aren't dramatic crashes. They're quiet misroutes: the model picks the wrong tool, or a tool fails with a vague message the model can't recover from. The agent then improvises, fabricates, or silently abandons the task.

This lesson dissects three anti-patterns that ship constantly in production:

• Minimal tool descriptions that leave the model guessing
• Too many tools per agent, which degrades selection reliability
• Generic error statuses that block intelligent recovery

Each one is a frequent wrong answer on the exam. Learn to spot and fix them.

A common misconception: the model routes by tool name. It does not. The tool description is the primary selection mechanism. Names are labels; descriptions are where the model decides whether a tool fits the situation.

A minimal description like "Looks up an order" tells the model almost nothing. When two tools have thin, overlapping descriptions, the model misroutes — it calls lookup_order when it needed get_customer, and the whole agentic loop drifts.