Server doesn't advertise tools capability when client sends empty capabilities in initialize #1185

Version

codebase-memory-mcp v0.9.0, Windows x64

Platform

Windows (x64)

Install channel

GitHub release archive / install.sh / install.ps1

Binary variant

ui

What happened, and what did you expect?

When a client sends an initialize request with capabilities: {} (empty object), the server responds with capabilities: {} and omits the tools field entirely. This means MCP clients (like Hermes Agent with MCP SDK 1.26.0) that check capabilities.tools in InitializeResult conclude the server has no tools and never call tools/list. The server's tools become invisible to the client.

Expected: Per the MCP specification, the server's capabilities in InitializeResult should describe what the server supports, regardless of what the client declares in its own capabilities. Since codebase-memory-mcp implements the tools/* request family, it should always include "tools": {"listChanged": false} (or equivalent) in its capabilities response. This is the standard behaviour of other MCP servers — they advertise their capabilities unconditionally.

Reproduction

The exact steps so we can reproduce it ourselves:

Step 1 — Start the server and send an initialize request with empty client capabilities:

Code
· bash
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"1.0"}}}' | codebase-memory-mcp
Actual output:

Code
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"protocolVersion": "2024-11-05",
"serverInfo": {"name": "codebase-memory-mcp", "version": "0.9.0"},
"capabilities": {}
}
}
(The server returns capabilities: {} — no tools field.)

Expected output:

Code
· json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"protocolVersion": "2024-11-05",
"serverInfo": {"name": "codebase-memory-mcp", "version": "0.9.0"},
"capabilities": {
"tools": {"listChanged": false}
}
}
}
(The server should always advertise tools since it implements the tools/* request family.)

Step 2 — For comparison, send initialize with client capabilities: {"tools": {}}:

Code
· bash
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{"tools":{}},"clientInfo":{"name":"test","version":"1.0"}}}' | codebase-memory-mcp
Output:

Code
· json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"protocolVersion": "2024-11-05",
"serverInfo": {"name": "codebase-memory-mcp", "version": "0.9.0"},
"capabilities": {
"tools": {"listChanged": false}
}
}
}
(This works correctly — server advertises tools because the client explicitly asked for them.)

No code indexing is needed to reproduce — this is a protocol-level bug in the MCP initialize handshake. Any MCP client that sends capabilities: {} (as MCP SDK v1.26.0 does) will fail to discover tools.

Logs

Diagnostics trajectory (memory / performance / leak issues)

Project scale (if relevant)

No response

Confirmations

• I searched existing issues and this is not a duplicate.
• My reproduction uses shareable code (a dummy snippet or a public OSS repository), not proprietary code.