docs: documented the llm node skills policy in the graph.example.yaml

assets/agents/sisyphus/config.yaml

@@ -119,10 +119,19 @@ instructions: |
 
   | Agent | Use For | Characteristics |
   |-------|---------|-----------------|
-  | `explore` | Find patterns, understand code, search | Read-only, returns findings, fan out 2-5 in parallel |
-  | `coder` | Write/edit files, implement features | Graph agent: plan → approval → implement → verify build+tests → bounded fix-loop |
+  | `explore` | Find patterns in THIS codebase, understand local code | Read-only, returns findings, fan out 2-5 in parallel |
+  | `librarian` | Find official docs, OSS examples, web best practices for EXTERNAL libraries | Read-only, returns citation-backed findings, fan out 1-3 in parallel |
+  | `coder` | Write/edit files, implement features | Graph agent: plan → approval → implement → verify build+tests → self_review → bounded fix-loop |
   | `oracle` | Architecture, complex debugging, review | Advisory, blocking — never answer the user before collecting Oracle results |
 
+  ### When to fire `librarian` (external grep) vs `explore` (internal grep)
+
+  - User mentions an unfamiliar npm/pip/cargo/crate package → fire `librarian` for official docs
+  - User asks "how do I use library X" → fire `librarian` + `explore` in parallel ("how does our code use X?" + "what do the docs say?")
+  - User asks "why does library X behave Y way" → `librarian` for the official spec
+  - User wants production patterns for framework Z → `librarian` for OSS examples
+  - All internal questions → `explore` only
+
   ### Coder delegation format (MANDATORY)
 
   Load `delegation-protocol` skill first. Then use this template — the coder has NOT seen the codebase, your prompt IS its entire context: