Result is a bare string

wrong-result-shape · Tools — execution

Endpoint (Streamable HTTP)

https://chaos-mcp.thomascdnns.com/s/wrong-result-shape/mcp

On the wire — recorded from a real request

Symptom

what you'll observe

Client can't find content[]; the result is a plain string, not the expected object.

Cause

what this reproduces

Returning the tool's value directly instead of wrapping it in {content:[{type:text,...}]}.

Fix

how you'd resolve it

Wrap tool output in the MCP result envelope with a typed content array.

Try it with curl

bash

curl -sS -X POST \
  https://chaos-mcp.thomascdnns.com/s/wrong-result-shape/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
      "protocolVersion": "2024-11-05",
      "capabilities": {},
      "clientInfo": {"name": "curl", "version": "1"}
    }
  }'