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

With no annotations, the description carries the full behavioral burden. It usefully discloses the pay-per-call cost ($0.005 USDC) and the endpoint path, which are real behavioral traits. However, it omits auth requirements, rate limits, error behavior, and pagination, leaving meaningful gaps for a paid 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?

The value proposition is front-loaded with the returned fields, followed by endpoint and cost in a compact arrow-delimited form. It is a single dense line with little waste, though the run-on enumeration is slightly hard to parse at a glance.

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?

No output schema exists, so the description must explain return values, and it does so thoroughly, including the sign convention for imbalance (>0 = more bids). For a two-parameter read tool it also covers cost and endpoint, leaving nothing essential missing.

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 coverage is 100%, so the schema already documents both symbol and limit (including the 5-100 range and default 20). The description only restates the symbol as a path segment and adds no syntax or format detail beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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?

States a specific resource (top-of-book order book for a crypto coin) and enumerates exactly what it returns: best bid/ask, mid price, spread (abs + bps), depth, and book imbalance. That enumeration inherently distinguishes it from siblings like crypto_price (last price only) and crypto_deep (deeper book), so an agent can tell what this is 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?

There is no explicit when-to-use/when-not guidance and no named alternative, despite numerous closely related siblings (crypto_price, crypto_deep, crypto_ohlcv). Usage is only implied by the returned fields. The endpoint path and pricing are operational details, not selection guidance.

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