# Adk Framework

> Skill: ADK Framework

- Skill: `izzyfresh/adk-framework` (Agent Skill)
- Install (CLI): `npx skillmds@latest add izzyfresh/adk-framework`
- Raw SKILL.md: https://api.skillmd.com/api/skills/izzyfresh/adk-framework/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: IzzyFresh (https://skillmd.com/u/izzyfresh)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/izzyfresh/adk-framework

---

# Skill: ADK Framework

This skill covers expert architectural patterns, routing strategies, and troubleshooting guidelines for the Google Agent Development Kit (ADK).

---

## 1. Multi-Agent Structure
*   **Discovery Rule:** Only the `root_agent` defined in `agent.py` or `root_agent.yaml` is automatically surfaced in the platform web UI. Sub-agents are invisible to the top-level application but are called natively via routing.
*   **Routing Rules:** Always provide the list of sub-agents directly to the parent agent via the `sub_agents` attribute. Do not construct wrapper functions to trigger a sub-agent manually.

## 2. Architectural Patterns
*   **Relay/Router Pattern:** 
    *   Design the orchestrator agent to act exclusively as a request classifier.
    *   Direct it to output strict XML-like signals (e.g., `<route>ROUTING_TO_RAG</route>`).
    *   Catch this signal in the main execution loop, running only the appropriate target agent to prevent nested agent call stacks and context pollution.
*   **Capabilities Discovery Pattern:** 
    *   When a user queries broad knowledge (e.g., "what do you know?"), trigger searches for broad index terms like "Overview" or provide a predefined hardcoded list of capabilities.

## 3. Routing Strategies
*   **File Presence Pattern:** Route to file-processing agents **only** if the user attaches a file or references "this attachment". Route to RAG/Knowledge agents for general queries and report generation.
*   **Strict Evaluation Order:** Categorize intents explicitly (e.g., `[1] DIRECT`, `[2] RAG`, `[3] CHAT`) and designate one specific category as the default fallback. Avoid negative constraint prompts.

## 4. Prompt Engineering Best Practices
*   **No Preamble Rule:** When an agent triggers a tool, harden the prompt to prohibit introductory filler (e.g., forbid saying "I can help with that"). Insist that the agent's first and only action must be to call the tool.