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

Annotations already declare readOnly/idempotent/non-destructive. The description adds meaningful context beyond them: auth requirements, 'Data, not a signal' framing, the main-dex exclusion rule, and the sort order. Pagination/rate-limit behavior is not mentioned, keeping it short of 5.

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-loads the core definition and example; the output-field enumeration is dense but informative given there's no output schema. Slightly long, but nearly every clause carries useful 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?

With no output schema, the description usefully enumerates the returned fields (legs, spread_apr_now/14d, basis_pct, min_leg_vol24_usd) and sort order. Auth and scope are covered; only edge-case behavior like empty results or rate limits is absent.

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% with only two optional params, both documented in the schema (limit, min_vol). The description doesn't add syntax or semantics beyond defaults, so the baseline 3 applies.

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 (assets listed on 2+ Hyperliquid HIP-3 dexes) with a concrete example, and explicitly excludes main-dex tickers. The sibling differentiation is explicit: 'for perp vs spot use carry_spot_perp'.

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?

Explicitly names when to use it ('the same ticker priced on 2+ HIP-3 dexes') and the alternative for the adjacent case ('for perp vs spot use carry_spot_perp'). It also states access prerequisites (Carry key, trial key, or x402 per call).

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