fix: instrument MCP List Tools spans in OpenAI Agents

[hashwnath]

Description

Fixes #4197

Problem: The OpenAI Agents SDK emits MCPListToolsSpanData spans when an agent fetches the list of tools from an MCP server, but the instrumentation did not handle this span data type. As a result, these spans appeared as "unknown" with operation_name="unknown" and no useful attributes.

Fix:

1. Import MCPListToolsSpanData in both the direct and fallback import blocks
2. Operation name: Maps to "mcp.list_tools"
3. Span kind: SpanKind.CLIENT (outgoing call to MCP server)
4. Span naming: Uses mcp.list_tools {server_name} format (e.g., mcp.list_tools Time)
5. Attributes: Extracts mcp.server.name, mcp.tools.count, and mcp.tools.list (list only when content capture is enabled)

Testing: Added unit test verifying operation name, span name, span kind, server attribute, and tools count for MCP list tools spans. All 104 existing tests continue to pass.

Note: A previous PR (#4285) attempted to fix this issue but was closed without merging. This PR takes a similar approach but integrates more completely with the existing patterns in the codebase, including proper span naming via get_span_name(), output type inference, and attribute extraction through the standard _extract_genai_attributes dispatch.

Type of Change

• Bug fix (non-breaking change which fixes an issue)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: hashwnath / name: Hashwanth S (49f3000)

[xrmx]

@hashwnath thanks for the pr, in order to contribute to this project you need to sign the CLA

[MikeGoldsmith]

Thanks for the PR @hashwnath!

The implementation follows the existing patterns well. However, a concern before approving is that a number of attributes don't align with the MCP semantic conventions that are already in the Python semconv package (opentelemetry/semconv/_incubating/attributes/mcp_attributes.py).

mcp.server.name is not a semconv attribute

The registered MCP attributes are mcp.method.name, mcp.protocol.version, mcp.resource.uri, and mcp.session.id. There is no mcp.server.name. The MCP span spec uses server.address for server identity.

mcp.tools.count and mcp.tools.list are not in semconv

These are custom attributes with no semconv backing. We should not add non-spec attributes. You're welcome to open a semconv proposal to suggest them if you think they'd be valuable.

Span name and operation name should follow MCP semconv

Per the MCP span spec, span names should follow {mcp.method.name} {target}. For this span type the method name is tools/list (McpMethodNameValues.TOOLS_LIST), so the span name should be tools/list Time rather than mcp.list_tools Time. The mcp.method.name attribute should also be set on the span.

The GenAIOperationName.MCP_LIST_TOOLS = "mcp.list_tools" value also diverges from the rest of the class (all others use underscores, e.g. agent_handoff) and isn't a defined gen_ai.operation.name value in the GenAI semconv.