Agent work is not just an access question anymore. It is becoming a runtime budget question.

This brief looks at Microsoft's Copilot Cowork general availability and Work IQ controls, then pairs that with Anthropic's statement that it is removing access to Fable 5 / Mythos 5 to ask a practical operator question:

If an agent can retrieve context, call tools, run longer tasks, and consume metered credits, who owns the budget gate before the work continues?

Run one Agent Runtime Budget Gate by June 24, 2026.

Use:

Microsoft Copilot Cowork GA: https://www.microsoft.com/en-us/microsoft-365/blog/2026/06/16/copilot-cowork-is-now-generally-available/
Microsoft Work IQ APIs: https://www.microsoft.com/en-us/microsoft-365/blog/2026/06/02/announcing-the-new-work-iq-apis/
Anthropic Fable/Mythos access-removal statement: https://www.anthropic.com/news/fable-mythos-access
OpenAI ChatGPT release notes: https://help.openai.com/en/articles/6825453-chatgpt-release-notes
OpenAI Memory FAQ: https://help.openai.com/en/articles/8590148-memory-faq/

Production disclosure: AI-assisted tools were used in parts of the research and production workflow. Final editorial judgment, risk posture, and release approval remain human-led. This is operational guidance, not legal advice.