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v2: Tool.execute and MCP.callTool spans no longer carry tool.name / tool.call_id #62305
Description
Description
In v2, the Tool.execute and MCP.callTool spans no longer say which tool ran. In v1 they had tool.name and tool.call_id (#22531, and #25452 for MCP and plugin tools). Since the v2 rewrite, Tool.execute in packages/core/src/tool.ts is a bare Effect.fn("Tool.execute"), and MCP.callTool in packages/core/src/mcp/index.ts has no attributes either.
In a trace backend, every tool call now looks the same: status and duration only. The only way to tell which tool a span ran is the error message, and only when the call fails (MCP tool "github-get_file_contents" on server "litellm" failed: …).
Expected: the attributes from v1, ideally also with the OTel GenAI names, so GenAI-aware backends can show the calls:
tool.name/gen_ai.tool.nametool.call_id/gen_ai.tool.call.idgen_ai.operation.name = execute_toolsession.id- for MCP: the server name, e.g.
mcp.server.name
The values are already in scope there (name, context.id, context.sessionID, input.server). The tool.execute.after hook receives them too.
Related: #46856 (trace context on MCP calls). Together these two would let MCP calls show up properly inside the agent trace.
Plugins
none
OpenCode version
2.1.2 (checked the code on v2.2.5)
Steps to reproduce
- Set
OTEL_EXPORTER_OTLP_ENDPOINTand runopencode runwith a prompt that uses a few tools (built-in and MCP). - Open the trace in any OTLP backend.
Tool.execute/MCP.callToolspans have notool.nameor call id. On v1 they did.
Operating System
Linux (container)
Terminal
n/a (opencode run)
Activity
opencodejr commentedon Nov 6, 2026
Thanks for the detailed report. I reproduced this on 2.1.2. A simulated model called the built-in
readtool and then a tool on a small local MCP server, with the OTLP export going to a local collector. BothTool.executeandMCP.callToolcame back with no attributes at all.On the latest
dev(21eaa62),Tool.executenow hasgen_ai.tool.name,gen_ai.tool.call.idandsession.id. The change is #60974, which isn't in a release yet (it isn't in v2.2.5). So the main problem, tool spans that don't say which tool ran, looks fixed, and the fix should be in the next release.Not everything you listed is there yet:
MCP.callToolstill has onlysession.id: no MCP server name or tool name. The parentTool.executespan has the namespaced tool name, e.g.echosrv_echo.tool.name/tool.call_idkeys andgen_ai.operation.namearen't set.If you need those, a feature request focused on them would be the best way to track it.
The bot will close this issue in 1 day unless you reply that it still happens, e.g. on a newer release.
opencodejr commentedon Nov 7, 2026
Closing this as completed, since there was no reply after a day. I reproduced it on 2.1.2:
Tool.executeandMCP.callToolwere exported with no attributes. On the latestdev(21eaa62),Tool.executenow hasgen_ai.tool.name,gen_ai.tool.call.idandsession.id, from #60974. That change isn't in a release yet, so it should ship in the next one.The extras you listed aren't there yet: an MCP server name or tool name on
MCP.callTool, the oldertool.name/tool.call_idkeys, andgen_ai.operation.name. If you need them, a separate feature request would be the best way to track that. If the missing tool name or call id still happens on a newer release, please comment here or open a new issue. Thanks for the detailed report!