ib-async-mcp

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connect

Establish connection to Interactive Brokers TWS or Gateway to enable account management, market data access, and trade execution through the ib-async MCP server.

Instructions

Connect to TWS or IB Gateway. Must be called before using other tools.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "connect"
  }
}

Input Schema

Name	Required	Description	Default
`host`	No	TWS/Gateway host	127.0.0.1
`port`	No	Port (7496 for TWS, 4001 for Gateway)
`client_id`	No	Client ID
`readonly`	No	Read-only mode

Implementation Reference

src/ib_async_mcp/server.py:450-460 (handler)

The handler logic for the 'connect' tool in _handle_tool function, which manages the connection to TWS/Gateway using IB.connectAsync.

if name == "connect":
    if ib is not None and ib.isConnected():
        return {"status": "already_connected"}
    ib = IB()
    await ib.connectAsync(
        host=args.get("host", "127.0.0.1"),
        port=args.get("port", 7496),
        clientId=args.get("client_id", 1),
        readonly=args.get("readonly", True),
    )
    return {"status": "connected", "accounts": ib.managedAccounts()}

src/ib_async_mcp/server.py:67-79 (schema)

Definition and schema of the 'connect' tool.

Tool(
    name="connect",
    description="Connect to TWS or IB Gateway. Must be called before using other tools.",
    inputSchema={
        "type": "object",
        "properties": {
            "host": {"type": "string", "default": "127.0.0.1", "description": "TWS/Gateway host"},
            "port": {"type": "integer", "default": 7496, "description": "Port (7496 for TWS, 4001 for Gateway)"},
            "client_id": {"type": "integer", "default": 1, "description": "Client ID"},
            "readonly": {"type": "boolean", "default": True, "description": "Read-only mode"},
        },
    },
),

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Mar 25, 2026

TDQS

A3.6/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, and the description only says 'Connect' without revealing idempotency, error handling, or side effects. Lacks detail critical for a connection tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two concise sentences with the verb front-loaded. No waste; every word earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

As a prerequisite tool, it should explain return behavior, success/failure indications, and reconnection. The description is too minimal given the importance and lack of output schema/annotations.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with descriptions for all parameters. The description does not add extra meaning beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it connects to TWS or IB Gateway, and specifies it must be called before other tools. This distinguishes it from siblings like 'disconnect' and 'is_connected'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states 'Must be called before using other tools,' providing clear when-to-use guidance. No exclusions, but the context is sufficient.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.