The image-gen plugin previously shipped only the MCP server, leaving the
model with no behavioral guidance for when/how to call the tools. As a
result the agent often described what it would generate instead of
calling generate_image, and didn't know that returned image_url blocks
render inline automatically.
Add a plugin-scoped agent and skill following the spark2-gamedev
pattern (auto-discovered via agents/ and skills/ directories):
- agents/image-gen-agent.md: trigger rules, tool selection, prompt
enhancement workflow, size inference, response patterns
- skills/prompt-craft/SKILL.md: 4 prompt templates (photorealistic,
artistic, design, concept art), enhancement strategies per subject
type (people/scenes/objects), zh→en translation guidance
The agent declares requiredMcpServers: [image-gen] so it only surfaces
when the MCP server is actually running.
Co-authored-by: 你的姓名 <you@example.com>
