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

Goes well beyond the readOnly/openWorld annotations: discloses a per-call price of 0.33 USDC on Base via x402 with the exact endpoint, states the operation takes seconds, and names data caveats (fees, spreads, borrow and basis excluded; blocked venues skipped and named). The payment/auth requirement is exactly the kind of behavioral fact an agent must know before invoking.

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?

Purpose and limits are front-loaded and the operational content is efficient. But roughly half the text is promotional/identity material — token contract address, two verification URLs, payout wallet, agent IDs — which does not help an agent decide or invoke, and dilutes the signal.

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, the description carries the return-value burden and does so by naming ranked gaps, per-venue rates and skipped venues. Combined with the disclosed limits and payment path, an agent has what it needs to call this correctly; only the shape of an individual gap record remains vague.

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 all four optional parameters already carry descriptions and defaults in the schema. The description lists the parameter names and repeats an example payload, adding no interpretation (units, interaction between coins and top_n) beyond what the schema provides.

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 verb and resource: compares live perp funding across Hyperliquid, OKX, Bitget, Gate, Binance and Bybit, normalized to APR, and lists the widest cross-venue gaps. The cross-venue comparison framing distinguishes it from single-venue siblings like hl_funding_snapshot without needing to name them.

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 audience is named ("for funding-rate researchers") and an example invocation is given, which implies the intended use. However, there is no explicit when-to-use/when-not-to-use guidance and no routing to alternatives such as hl_funding_snapshot or trade_strategy_consult.

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