docs: clarify OpenTelemetry spans for resources and prompts

Author: Joosboy

docs/run/opentelemetry.md

@@ -11,12 +11,14 @@ call `MCPServer(...)`.
 ```
 
 That is a complete, traced server. Call `search_books` and a span is created for it. The same is
-true for the low-level `Server`: the tracing lives on both.
+true when a client reads `catalog://featured` or renders `reading_prompt`. The low-level `Server`
+is traced too.
 
 ## What you get
 
-Every inbound message becomes a `SERVER` span named after the method and its target. So a
-`tools/call` for `search_books` is the span `tools/call search_books`, and a bare `tools/list`
+Every inbound message becomes a `SERVER` span named after the method, plus a target for named
+operations. So a `tools/call` for `search_books` is the span `tools/call search_books`,
+a `prompts/get` for `reading_prompt` is `prompts/get reading_prompt`, and a bare `tools/list`
 is just `tools/list`.
 
 Each span carries a few attributes:
@@ -31,13 +33,25 @@ OpenTelemetry's [GenAI semantic conventions](https://opentelemetry.io/docs/specs
 * `gen_ai.operation.name`, set to `"execute_tool"`.
 * `gen_ai.tool.name`, set to the tool being called.
 
-A `prompts/get` span gets `gen_ai.prompt.name` in the same spirit. The list methods carry no
+A `prompts/get` span gets `gen_ai.prompt.name` in the same spirit. `resources/read` spans are
+created by the same middleware and carry the common `mcp.*` attributes; the SDK does not add the
+resource URI to the span name or to a `gen_ai.*` attribute today. The list methods carry no
 `gen_ai.*` keys, because there is nothing to name.
 
 !!! tip
     Those GenAI attributes are the reason a tracing UI groups your tool calls the way it groups
     any other agent's. You get that grouping for free, with no extra code.
 
+## Adding your own detail
+
+The SDK span wraps the request handler. That means a tool, resource, or prompt function runs with
+the SDK-created span already current.
+
+If you need more detail than the default attributes provide, create child spans inside your handler
+or in your own middleware. For example, a resource handler can add a child span for a database read,
+and a prompt handler can add one for template assembly. Those spans nest under `resources/read` or
+`prompts/get`, so a tracing backend still shows one connected request.
+
 ## It costs nothing until you want it
 
 Here is the part that makes "on by default" a comfortable default.

docs_src/opentelemetry/tutorial001.py

@@ -7,3 +7,15 @@
 def search_books(query: str) -> str:
     """Search the catalog by title or author."""
     return f"Found 3 books matching {query!r}."
+
+
+@mcp.resource("catalog://featured")
+def featured_books() -> str:
+    """The featured books shelf."""
+    return "Dune\nThe Left Hand of Darkness\nA Wizard of Earthsea"
+
+
+@mcp.prompt()
+def reading_prompt(topic: str) -> str:
+    """Create a reading recommendation prompt."""
+    return f"Recommend one book about {topic}."

tests/docs_src/test_opentelemetry.py

@@ -24,6 +24,26 @@ async def test_a_plain_server_is_traced_with_no_extra_code(capfire: CaptureLogfi
     assert attributes["gen_ai.tool.name"] == "search_books"
 
 
+async def test_resources_and_prompts_are_traced_at_the_request_level(capfire: CaptureLogfire) -> None:
+    """tutorial001: resource reads and prompt renders use request-level SERVER spans."""
+    async with Client(tutorial001.mcp) as client:
+        await client.read_resource("catalog://featured")
+        await client.get_prompt("reading_prompt", {"topic": "Dune"})
+
+    spans = {s["name"]: s for s in capfire.exporter.exported_spans_as_dict()}
+
+    resource_attributes = spans["resources/read"]["attributes"]
+    assert resource_attributes["mcp.method.name"] == "resources/read"
+    assert "gen_ai.operation.name" not in resource_attributes
+    assert "gen_ai.prompt.name" not in resource_attributes
+    assert "gen_ai.tool.name" not in resource_attributes
+
+    prompt_attributes = spans["prompts/get reading_prompt"]["attributes"]
+    assert prompt_attributes["mcp.method.name"] == "prompts/get"
+    assert prompt_attributes["gen_ai.prompt.name"] == "reading_prompt"
+    assert "gen_ai.operation.name" not in prompt_attributes
+
+
 async def test_client_and_server_share_one_trace(capfire: CaptureLogfire) -> None:
     """When both sides run the SDK, the client and server spans land in one trace (SEP-414)."""
     async with Client(tutorial001.mcp, mode="legacy") as client: