mb_get_orderbook

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 states that the tool returns asks and bids with prices and quantities, which is essentially restating the tool's purpose. It does not disclose any additional behavioral traits such as default limit behavior, result ordering, pagination, or potential errors (e.g., invalid symbol). This is a significant gap for a read operation without annotation support.

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 a single, well-structured sentence that is concise and front-loaded with the key action and resource. Every word adds value, and there is no redundant information. It is appropriately sized for a simple read tool.

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?

The tool is simple with only two parameters, and the schema covers both fully. However, there is no output schema, so the description should ideally provide more detail about the return structure. It does mention asks/bids and prices/quantities, which gives a general idea, but it does not explain how the limit parameter affects the response or whether there is a default limit. Given the tool's simplicity, this is adequate but not complete.

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 both parameters (symbol and limit). The description adds some meaning by explaining that the trading pair is for a pair like BTC-BRL and that the return contains orders with prices and quantities, but it does not add semantics for the limit parameter beyond what the schema provides. Baseline 3 is appropriate.

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 identifies the tool as retrieving the order book (asks and bids) for a trading pair on Mercado Bitcoin. It uses a specific verb ('Get'), specifies the resource ('order book'), and differentiates it from sibling tools like mb_get_trades (which retrieves trades) and mb_get_tickers (which gets ticker info).

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 clearly implies when to use this tool: when you need current buy and sell orders with prices and quantities for a trading pair. It does not explicitly mention alternatives or when not to use it, but the context is clear enough that an agent can infer the appropriate use case.

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