Binance.US MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively communicates critical behavioral traits: it requires a specific API key ('REQUIRES CUSTODIAL SOLUTION API KEY'), initiates an external process ('This initiates a transfer request to your custody partner!'), and clarifies that execution is handled externally ('The actual transfer is executed by the custody partner.'). This covers authentication needs and process ownership, though it lacks details on rate limits, error handling, or response format.

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

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

The description is appropriately sized with four sentences that are front-loaded with the core purpose. The warning emojis and capitalized text effectively highlight critical information without unnecessary verbosity. However, the third sentence ('This requests your custodial partner to transfer assets to your Binance.US account.') slightly repeats the first sentence, reducing efficiency.

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

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

Given the tool's complexity (financial transfer with external dependencies) and lack of annotations and output schema, the description is moderately complete. It covers the purpose, prerequisites, and behavioral context well, but it does not explain the return values, error conditions, or specific operational constraints like timing or limits. For a tool initiating external transfers, more detail on outcomes would be beneficial.

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

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

Schema description coverage is 100%, so the schema already documents all parameters (rail, asset, amount, clientOrderId) with descriptions. The description does not add any parameter-specific semantics beyond what the schema provides, such as examples for 'rail' or constraints on 'amount'. The baseline score of 3 is appropriate since the schema handles the heavy lifting, but the description does not compensate with additional insights.

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

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

The description clearly states the specific action ('Request asset transfer') and resources involved ('from a custodial partner account to Binance.US custodial sub-account'). It distinguishes itself from sibling tools like 'binance_us_custodial_wallet_transfer' by specifying the source as a custodial partner rather than a wallet, and from 'binance_us_custodial_custodian_transfer_history' by focusing on initiating transfers rather than viewing history.

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

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

The description provides clear context for when to use this tool ('Request asset transfer from a custodial partner account to Binance.US') and includes warnings about prerequisites ('REQUIRES CUSTODIAL SOLUTION API KEY') and implications ('This initiates a transfer request to your custody partner!'). However, it does not explicitly mention when NOT to use it or name specific alternatives among the many sibling tools, such as distinguishing from 'binance_us_custodial_wallet_transfer' for internal transfers.

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