docs: document summon extension requirement for delegate and load tools (#9231)

Signed-off-by: Douwe Osinga <douwe@squareup.com> Co-authored-by: Douwe Osinga <douwe@squareup.com>
2026-05-16 10:41:15 -04:00
parent 3cf0bcdec7
commit 3254d442c9
3 changed files with 29 additions and 0 deletions
@@ -176,6 +176,18 @@ The `extensions` field allows you to specify which Model Context Protocol (MCP)
 - **`frontend`**: Frontend-provided tools called through the frontend
 - **`inline_python`**: Inline Python code executed using uvx. Requires `code` field; optional `dependencies` for packages.

+:::note Summon Extension and Subagents
+The `delegate` and `load` tools are provided by the `summon` platform extension. When a recipe specifies an explicit `extensions` block, only the listed extensions are available — default platform extensions like `summon` are not automatically included. If your recipe needs subagent delegation, add `summon` to your extensions list:
+
+```yaml
+extensions:
+  - type: platform
+    name: summon
+```
+
+Recipes that define [`sub_recipes`](/docs/guides/recipes/subrecipes) have `summon` auto-injected and do not need to list it explicitly.
+:::
+
 #### Example Extensions Configuration

 <Tabs groupId="format">