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

Goes well beyond the annotations by disclosing threshold source (/api/market-state), the empty-result shape ('nothing abnormal with what was checked'), and a non-obvious failure semantic: stale source with no other findings returns 503 instead of a false all-clear. It also discloses cost (0.02 USDC per call, x402 payment rails) and that error responses are never billed — precisely the operational facts an agent needs before calling 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?

Three sentences, front-loaded with the usage trigger, then the return contract, then error/payment semantics in descending order of importance. No sentence restates the title or wastes space on the read-only nature already covered by annotations.

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 an output schema present, the description needn't explain return fields, and it doesn't. It still supplies the three things the schema and annotations cannot: what is measured, the 503-instead-of-all-clear edge case, and the per-call price and payment chain — complete for a zero-parameter paid read tool.

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?

Zero parameters with 100% schema coverage, so there is nothing for the description to disambiguate. The description correctly implies no inputs are required and instead spends its words on scope and cost.

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 scope ('what is abnormal across Hyperliquid perps right now') and the exact output shape: funding, liquidation and open-interest anomalies in one ranked list. The 'one check / one ranked list' framing implicitly differentiates it from the per-metric siblings (get_funding_extremes, get_oi_spike_scan, get_liq_heatmap), but no sibling is named explicitly.

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?

'Use when an agent needs one check for what is abnormal' gives a clear triggering condition, and the aggregation framing points to it over single-metric tools. There is no explicit when-not or named alternative, so the routing is inferred rather than stated.

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