docs: clarify think tool is for models without native reasoning

The documentation previously recommended including the think tool in every
agent. In reality, it is only useful for models that lack built-in
reasoning capabilities (e.g., smaller or older models). Models with
native thinking — such as Claude with extended thinking, OpenAI o-series,
or Gemini with a thinking budget — do not need it.

Update docs across three files to reflect this:
- docs/tools/think: reword overview and tip to explain when to use it
- docs/guides/tips: rename section and clarify it targets non-reasoning models
- docs/concepts/multi-agent: qualify the best-practice bullet as conditional

Fixes #2190

Assisted-By: docker-agent

Author: dgageot

docs/concepts/multi-agent/index.md

@@ -211,7 +211,7 @@ toolsets:
 - **Keep agents focused** — Each agent should have a clear, narrow role
 - **Write clear descriptions** — The coordinator uses descriptions to decide who to delegate to
 - **Give minimal tools** — Only give each agent the tools it needs for its specific role
-- **Use the think tool** — Give coordinators the think tool so they reason about delegation
+- **Use the think tool when needed** — For models without native reasoning, give coordinators the think tool so they reason about delegation. Models with built-in thinking (e.g., via `thinking_budget`) don't need it
 - **Use the right model** — Use capable models for complex reasoning, cheap models for simple tasks
 
 <div class="callout callout-info">

docs/guides/tips/index.md

@@ -169,16 +169,16 @@ agents:
 - Order by preference (best first)
 - Include a cheaper/faster model as last resort
 
-### Use Think Tool for Complex Tasks
+### Use Think Tool for Non-Reasoning Models
 
-The `think` tool dramatically improves reasoning quality with minimal overhead:
+The `think` tool provides a reasoning scratchpad for models that lack built-in thinking capabilities:
 
 ```yaml
 toolsets:
-  - type: think # Always include for complex agents
+  - type: think # Useful for models without native reasoning
 ```
 
-The agent uses it as a scratchpad for planning and decision-making.
+The agent uses it as a scratchpad for planning and decision-making. If your model already supports a [thinking budget]({{ '/configuration/models/#thinking-budget' | relative_url }}) (e.g., Claude with extended thinking, OpenAI o-series, Gemini with thinking enabled), you don't need this tool — the model can reason internally.
 
 ## Security Tips
 

docs/tools/think/index.md

@@ -12,7 +12,7 @@ _Step-by-step reasoning scratchpad for planning and decision-making._
 
 The think tool is a reasoning scratchpad that lets agents think step-by-step before acting. The agent can write its thoughts without producing visible output to the user — ideal for planning complex tasks, breaking down problems, and reasoning through multi-step solutions.
 
-This is a lightweight tool with no side effects. It's recommended for all agents — it improves the quality of reasoning on complex tasks at minimal cost.
+This is a lightweight tool with no side effects. It is most useful for models that lack built-in reasoning or thinking capabilities (e.g., smaller or older models). For models that already support native thinking — such as Claude with extended thinking, OpenAI o-series, or Gemini with a thinking budget — this tool is unnecessary since the model can reason internally.
 
 ## Configuration
 
@@ -24,7 +24,7 @@ toolsets:
 No configuration options.
 
 <div class="callout callout-tip">
-<div class="callout-title">💡 Tip
+<div class="callout-title">💡 When to use
 </div>
-  <p>Include the think tool in every agent. It adds minimal overhead while significantly improving reasoning quality on complex tasks.</p>
+  <p>Use the think tool with models that don't have native reasoning capabilities. If your model already supports a <a href="{{ '/configuration/models/#thinking-budget' | relative_url }}">thinking budget</a>, you likely don't need this tool.</p>
 </div>