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 describes the tool's behavior: it's a read operation (implied by 'Get'), discloses authentication requirements (custodial API key needed), and details the return structure including specific balance fields and their meanings. It lacks information on rate limits, error conditions, or pagination, but provides substantial context beyond basic purpose.

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 well-structured and appropriately sized. It front-loads the core purpose, follows with a critical warning, then details the return values. Every sentence adds value: the first states what it does, the second provides essential prerequisites, and the remaining sentences explain the output structure clearly without redundancy.

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 moderate complexity (retrieving balance data from two sources), no annotations, and no output schema, the description does a good job of being complete. It explains the purpose, prerequisites, and detailed return structure. It could improve by mentioning potential errors or rate limits, but covers the essential context well for a read operation.

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?

The input schema has 100% description coverage, clearly documenting the single required 'rail' parameter. The description does not add any parameter-specific information beyond what the schema provides. According to scoring rules, when schema coverage is high (>80%), the baseline score is 3 even with no param info in the description.

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 tool's purpose with specific verbs ('Get balance information') and resources ('Binance.US exchange wallet and custodial sub-account'). It distinguishes from sibling tools like 'binance_us_cust_balance' by specifying it returns both exchange wallet and custodial sub-account balances, not just custodial.

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 explicit context for when to use this tool (to get balance information for both exchange wallet and custodial sub-account) and includes a critical prerequisite warning about requiring a custodial solution API key. However, it does not explicitly state when not to use it or name specific alternatives among the many sibling tools.

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