get_order_book

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

With no annotations provided, the description carries the full burden. It adds useful output behavior context beyond the name ('including best bid/ask, mark price, and funding rate for perpetuals') and even hints at conditional behavior for perpetuals. However, it says nothing about default depth behavior, response shape, or error cases, which would matter for a market data endpoint.

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?

One sentence of 21 words with zero filler. The core action and resource are front-loaded, and the 'including' clause adds differentiating value about return contents. Every word earns its place.

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?

For a low-complexity, two-parameter getter with full schema coverage and no output schema, this description covers the essential contract: what the tool returns and for which instruments. Minor gaps remain — no mention of the default depth when omitted or the exact structure of the response — but these are small for a read-only market data tool.

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 fully documents both parameters — instrument_name and depth with its allowed level values. The description adds no new parameter meaning; it only clarifies at a high level that the tool returns bids and asks. Baseline 3 is appropriate since the structured schema carries the load.

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?

Uses a specific verb and resource: 'Get the order book (bids and asks) for an instrument.' The scope qualifier 'for an instrument' distinguishes it from sibling get_book_summary_by_currency, and the mention of mark price and funding rate for perpetuals separates it from get_ticker. An agent can identify the correct tool without opening the schema.

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 conveys implied usage — get this when you need order book levels, best bid/ask, mark price, or funding rate for an instrument — but it never explicitly names alternatives or states when not to use it. No exclusions are given versus get_ticker or get_book_summary_by_currency, leaving the agent to infer selection criteria from the field list.

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