Broken MCP Tool Call
Use when an MCP initialize, tools/list, tools/call, resources/read, or prompts/get workflow fails.
Linked toolsok
Commandsok
MCPTraceClaws
Symptoms
- MCP method span failed.
- tools/call result is absent or redacted error only.
- MCP client reports JSON-RPC error.
Likely Causes
- Invalid JSON-RPC envelope.
- Tool is protected and no PLATPHORM_API_KEY was supplied.
- Tool handler returned a real degraded adapter state.
Checks
- POST /api/mcp initialize.
- POST /api/mcp tools/list.
- Inspect the tools/call span arguments after redaction.
Evidence To Collect
- JSON-RPC id
- method
- tool name
- redacted arguments
- response error code
platphormctl Commands
platphormctl mcp validate trace platphormctl trace get <traceId>