Fix stale MCP skill guidance and OAuth onboarding

[Mike-Medvedev]

Description

Agents can follow stale training tools, unnecessarily hand off complex Workflows, or misconfigure API-key fallback; align the existing skills and onboarding with current MCP behavior, including testing drafts without publishing.

Type of change

• Documentation and guidance fix.

How has this change been tested?

• Four Cowork package tests passed; skill format checks passed.
• Checked 17 referenced tools against the current MCP catalog and verified local/resource links in edited markdown.
• No new tests: changes are prose and the MCP configuration note only.

Any specific deployment considerations

• Refresh the installed skills/plugin; deploy MCP after merge to refresh hosted skill resources through the existing release flow.
• No deployment workflow or submodule pin changes.
• Companion MCP guidance update: https://github.com/roboflow/roboflow-mcp/pull/178.