Market Order Book

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

Annotations already mark this as readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds useful behavioral context by specifying that it returns bid/ask depth with levels and sizes on both sides. It does not overpromise or contradict the annotations.

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?

Two sentences with no wasted words. The primary action and resource are front-loaded, and the second sentence adds practical value by stating the intended use case. No redundant restating of the tool name or schema.

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 simple read-only market data tool, the description explains what the tool returns and why it is useful. There is no output schema, but the returned shape is summarized well enough. The only minor gap is lack of explicit mention of snapshot/current nature, but this is strongly implied by 'order book.'

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%, and parameter descriptions are already detailed, including symbol format examples and depth constraints. The tool description adds no parameter-level detail, but it does not need to because the schema already carries that burden.

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 opens with a specific verb and resource: 'Get the order book (bid/ask depth) for any trading pair on Hyperliquid.' It clearly states what data is returned ('price levels and sizes on both sides'), making it easy to distinguish from sibling market tools like market_price or market_historical_oi.

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 gives clear use-case context: 'Essential for understanding liquidity, spread, and potential support/resistance.' It does not explicitly name alternatives or exclusion criteria, but the use cases are specific enough for an agent to infer when this tool is appropriate.

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