INVOKE THIS SKILL when building ANY Deep Agents application. Covers create_deep_agent(), harness architecture, SKILL.md format, and configuration options.
SkillScore95Maintained
Automatic
◆AI Engineer pack
Last verified 8/19/2026
What it changes
Passed 21 of 22 test cases with the skill, and 7 of 22 without it.
Without skill32%
With skill95%
Checks it passed that the model alone missed
Identifies TodoListMiddleware
Identifies SubAgentMiddleware
Identifies FilesystemMiddleware
and 13 more in the full report
15 fixed6 passed either way0 still failing1 broke
Pass-rate lift
+64 pp
Tokens
+84%
Agent turns
0%
Response time
-59%
Model gemini-3.6-flashMeasured 8/19/2026v121 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 15 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 15
Prompt
Which middleware component is responsible for delegating execution tasks to specialized child agents?
What was checked, without and with the skill
Checked
Without skill
With skill
Identifies SubAgentMiddleware
Missed
Passed
case-17 · gemini-3.6-flash · 8/19/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md418 linessingle file
Task Planning: TodoListMiddleware for breaking down complex tasks
Context Management: Filesystem tools with pluggable backends
Task Delegation: SubAgent middleware for spawning specialized agents
Long-term Memory: Persistent storage across threads via Store
Human-in-the-loop: Approval workflows for sensitive operations
Skills: On-demand loading of specialized capabilities
The agent harness provides these capabilities automatically - you configure, not implement.