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

Annotations already declare read-only, open-world, idempotent, and non-destructive behavior, but the description adds important context: the endpoint is paid ($0.0025), returns x402 payment requirements and a URL, and provides a free sample response. It does not detail rate limits or the full post-payment response shape, but it is substantially more transparent than the annotations alone.

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 front-loaded with cost and data scope, then gives usage guidance, return behavior, and a sample link. Every sentence earns its place, and the dense parenthetical details are relevant rather than wasteful.

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?

With no output schema and no parameters, the description covers what the tool returns at a high level: funding-rate extremes, open interest, volume filter, watchlist, and x402 payment requirements. The sample link helps, though the exact response structure after payment is not fully spelled out.

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 tool has zero parameters, so parameter semantics are inherently minimal and the schema does not need compensation. The description also explains the implicit filtering constraints (top 10 extreme rates, >$1M 24h volume, fixed watchlist), which is useful context even though no parameters exist.

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 states a specific resource and scope: the 10 most extreme Hyperliquid funding rates right now, including annualized percentages, open interest in USD, and a volume threshold. It also names the watchlist assets and distinguishes itself from historical funding siblings through 'right now' and 'most extreme'.

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?

It gives clear use cases: spotting crowded longs/shorts and squeeze risk before a trade, or running a funding-arbitrage scan. It does not explicitly name when not to use it or point to alternatives such as get_funding_history, so it stops short of full routing guidance.

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