MCP tools | LUCA Plus

The remote endpoint is POST /mcp on each LUCA agent host. The MCP endpoint is public. It needs no Basic Auth password. It uses JSON-RPC 2.0 over Streamable HTTP. The server is stateless. MCP and REST API calls share a limit of 100 requests per client IP in each fixed minute. After that, HTTP 429 includes Retry-After. If the limiter is unavailable, the endpoint returns HTTP 503. It sends one JSON response for each request and does not send server events.

Tool	Input	Result
`get_product_overview`	none	Sourced product topics
`search_knowledge`	`query`	Matching facts and source URLs
`answer_question`	`question`	Short answer, source URLs, and official next steps
`assess_fit`	`goal`, `active_abn`, `gst_registered`, `accounting`	Nonbinding notes and official links
`get_next_steps`	optional `goal`	Steps and official links
`get_topic`	`id`	One source-backed fact, scope, and review state
`compare_paths`	none	Three product paths for a visitor goal
`get_source_conflicts`	none	Unresolved public claims to check with LUCA

All tools are read-only. The server accepts no personal or bank details. For protocol 2026-07-28, send _meta in each request and matching HTTP headers. Call server/discover before tools/list if the client needs the server description.

For a modern tool call, send these headers:

Content-Type: application/json
Accept: application/json, text/event-stream
MCP-Protocol-Version: 2026-07-28
Mcp-Method: tools/call
Mcp-Name: search_knowledge

Send this JSON body:

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "search_knowledge",
    "arguments": { "query": "GST requirements" },
    "_meta": {
      "io.modelcontextprotocol/protocolVersion": "2026-07-28",
      "io.modelcontextprotocol/clientInfo": {
        "name": "example",
        "version": "1.0"
      },
      "io.modelcontextprotocol/clientCapabilities": {}
    }
  }
}

The JSON-RPC result includes resultType, content, structuredContent, and isError. The tool returns source URLs in its structured result. The result can say isError: true for a bad search query. The server validates all tool arguments against the published schemas. The get_topic result has topic_not_found when the ID is unknown on that brand.

The compatibility path accepts initialize for protocol 2025-03-26. It also accepts tools/list and tools/call after that step. The server does not use sessions.

Tool results include a text block with JSON. They also include structuredContent for clients that use structured results.

The MCP server checks the Origin header when a client sends one. Call the server from a trusted client or use the local CLI process. The local process needs a network connection because it sends tool calls to the remote Worker.