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

No annotations, so the description carries the full burden. It does disclose cost and payment mechanism ($0.003 USDC per call via x402 on Base), which is genuine behavioral context an agent needs before calling, plus the default OI filter. But it says nothing about output ordering, freshness of rates, or failure modes.

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?

A single front-loaded sentence names the resource, scope, and filter, followed by one short pricing sentence. Nothing is redundant, though the pricing clause reads as appended rather than integrated.

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 2-parameter read tool with no annotations and no output schema, the definition covers inputs and cost but not return shape: an agent cannot tell whether rows include symbol, venue, rate, and OI, or how the two 'sides' are returned (the limit description's 'rows per side' is the only hint).

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 both parameters (limit, minOiUsd) are already documented in the schema; baseline 3 applies. The description restates the $5M default and clarifies that open interest is expressed in USD, but adds no format or boundary detail beyond the schema.

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 and scope: highest/lowest annualized funding rates across Binance USDT-margined perpetuals and Hyperliquid perps, with open interest. That scope naturally separates it from the perps_funding and perps_oi siblings, but neither is named explicitly, so an agent must infer the routing.

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 'highest and lowest' framing implies a screener/ranking use case, but there is no explicit when-to-use guidance, no exclusions, and no pointer to perps_funding (single-asset funding) or perps_oi when those would be more appropriate.

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