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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, and the description adds substantial context beyond them: paywall/auth path, the lognormal-diffusion modeling assumption, duplicate-listing collapsing, price-ladder consistency checks, and the notable disclosure that extreme-tail rows are flagged rather than asserted. That last point tells an agent exactly how much to trust the output.

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?

Front-loading the PREMIUM/auth banner is correct, and every sentence carries information — methodology, edge cases, disclaimer. It is dense to the point of being a run-on list of clauses, but there is no filler to cut.

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?

An output schema exists, so return shape needn't be restated, and the description covers auth, method, and caveats well. The remaining gap is operational: nothing on what happens with an empty result set or how many markets are scanned, which matters for a six-parameter analytics 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?

Schema coverage is 67%, and the description compensates for the gaps: 'ranked by edge' implies limit is top-N by edge, 'Optionally use perp funding as drift' maps to useFundingDrift, and 'sensitivity to the volatility input' motivates volInterval/volWindowDays. It still leaves volInterval's 1h/4h/1d trade-off and limit's cap behavior unaddressed.

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 verb and resource pair: compare Polymarket price-threshold odds against Hyperliquid-implied probability, and it enumerates concrete outputs (ranked mispricings, ladder-consistency checks, dedup, sensitivity). No sibling in the list does cross-venue odds-vs-vol comparison, so it is distinguishable without opening the schema.

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 a clear precondition ('call hl_request_free_key first... or pay per call via x402') and an implicit trigger (you want cross-market mispricing ranked by edge). However, it never names an alternative for adjacent needs — e.g. hl_score_calibration or hl_get_markets — nor states when this tool is the wrong choice.

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