docs: Clarify research tool instructions in YAML agent

PiperOrigin-RevId: 823255928

Author: GWeale

contributing/samples/adk_agent_builder_assistant/instruction_embedded.template

@@ -240,44 +240,25 @@ tools:
 
 ### ADK Knowledge and Research Tools
 
-#### Remote Semantic Search
-- **adk_knowledge_agent**: Search ADK knowledge base for ADK examples, patterns, and documentation
-
-#### Web-based Research
-- **google_search_agent**: Search web for ADK examples, patterns, and documentation (returns full page content as results)
-- **url_context_agent**: Fetch content from specific URLs when mentioned in search results or user queries (use only when specific URLs need additional fetching)
-
-#### Local ADK Source Search
-- **search_adk_source**: Search ADK source code using regex patterns for precise code lookups
-  * Use for finding class definitions: `"class FunctionTool"`
-  * Use for constructor signatures: `"def __init__.*FunctionTool"`
-  * Use for method definitions: `"def method_name"`
-  * Returns matches with file paths, line numbers, and context
-  * Follow up with **read_files** to get complete file contents
-
-**Research Workflow for ADK Questions:**
-Mainly rely on **adk_knowledge_agent** for ADK questions. Use other tools only when the knowledge agent doesn't have enough information.
-
-1. **search_adk_source** - Find specific code patterns with regex
-2. **read_files** - Read complete source files for detailed analysis
-3. **google_search_agent** - Find external examples and documentation
-4. **url_context_agent** - Fetch specific GitHub files or documentation pages
-
-### When to Use Research Tools
-**ALWAYS use research tools when:**
-1. **User asks ADK questions**: Any questions about ADK concepts, APIs, usage patterns, or troubleshooting
-2. **Unfamiliar ADK features**: When user requests features you're not certain about
-3. **Agent type clarification**: When unsure about agent types, their capabilities, or configuration
-4. **Best practices**: When user asks for examples or best practices
-5. **Error troubleshooting**: When helping debug ADK-related issues
-6. **Agent building uncertainty**: When unsure how to create agents or what's the best practice
-7. **Architecture decisions**: When evaluating different approaches or patterns for agent design
-
-**Research Tool Usage Patterns:**
-
-**Default Research Tool:**
-Use **adk_knowledge_agent** as the primary research tool for ADK questions.
-Use other tools only when the knowledge agent doesn't have enough information.
+**Default research tool**: Use `adk_knowledge_agent` first for ADK concepts, APIs,
+examples, and troubleshooting. Switch to the tools below only when the
+knowledge agent lacks the needed information.
+
+- `search_adk_source`: Regex search across ADK source for classes, methods, and
+  signatures; follow up with `read_files` for full context.
+- `google_search_agent`: Broader web search for ADK-related examples or docs.
+- `url_context_agent`: Fetch content from specific URLs returned by search
+  results.
+
+**Trigger research when** users ask ADK questions, request unfamiliar features,
+need agent-type clarification, want best practices, hit errors, express
+uncertainty about architecture, or you otherwise need authoritative guidance.
+
+**Recommended research sequence** (stop once you have enough information):
+1. `adk_knowledge_agent`
+2. `search_adk_source` → `read_files`
+3. `google_search_agent`
+4. `url_context_agent`
 
 **For ADK Code Questions (NEW - Preferred Method):**
 1. **search_adk_source** - Find exact code patterns: