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

With readOnlyHint/openWorldHint already declared, the description adds genuinely useful context the annotations cannot: the sampling window (latest 100 fills, not a 24h total), the single-venue limit, and the commercial model ($0.002 USDC per successful call via x402 on Base/Solana/Arc, failed calls free). Cost and billing semantics are exactly the kind of behavior an agent needs 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?

Three dense sentences, front-loaded with what the tool returns before constraints and pricing. Minor redundancy between 'for one underlying' and 'Covers OKX only', but every sentence still carries distinct information.

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?

Output schema exists so return-value detail is not needed, and annotations cover the safety profile. The description fills the remaining gaps an agent needs for a paid, venue-limited feed: data window, venue scope, and per-call cost with failure handling.

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% and the sole parameter 'uly' is already documented with examples, so the schema carries the weight. The description only reinforces that a single underlying is accepted ('for one underlying (e.g. BTC-USD)'), adding marginal meaning 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 verb+resource: OKX perpetual-swap liquidations for one underlying, with the metric breakdown (long vs short liquidated USD) and the payload (largest events). It is immediately distinguishable from siblings like crypto_binance_orderbook_depth or crypto_hyperliquid_perps_depth, which are depth tools on other venues.

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?

Gives explicit boundaries: 'Covers OKX only' and 'the window is the latest 100 events, not a fixed 24h total', plus 'Other exchanges' liquidation streams are not reported'. This tells an agent when not to use it and prevents misreading the result as a 24h aggregate; the only gap is that no alternative tool is named (none exists among the siblings).

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