Claude Desktop whatif sim_evaluate
How to: Claude Desktop whatif sim_evaluate
Add whatif to Claude Desktop
-
01
Open ~/Library/Application Support/Claude/claude_desktop_config.json and merge this in. Keep any servers already there.
{
"mcpServers": {
"whatif": {
"command": "npx",
"args": [
"-y",
"mcp-remote",
"https://sim.pflow.xyz/mcp"
]
}
}
}-
02
Save the file and restart Claude Desktop.
-
03
Ask for something sim_evaluate does. Claude Desktop lists the server's tools on connect and calls sim_evaluate itself — you do not invoke it by name.
-
04
If nothing happens, check the server is running and that whatif's identifier in your config matches the one above exactly.
Claude Desktop has no remote transport in its config file, so this bridges through mcp-remote. Restart the app after saving. Claude Desktop docs
Same tool, other clients
This list was read from the server itself, by connecting to it and calling tools/list on 24 September 2026. It is what
the server actually exposes, not what its listing claims.
Mutating and Read-only are read off each tool's name, not its schema — a hint, not a guarantee. The registry stores tool names only; connect the server for its live schemas.