An agent has grown to 22 tools and selection accuracy has degraded across the board — not between any specific pair. What's the right diagnosis?

Answer: B — Tool overload — past roughly 4-5 tools, selection degrades on decision complexity alone

Read the condition carefully. Better descriptions fix the case where the model can't tell two tools apart. They don't fix a toolkit that's simply too large — that needs splitting across subagents or narrowing the toolset.