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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description adds real value beyond that by disclosing data provenance (top 120 accounts by 30-day PnL from the public leaderboard), freshness signals (snapshot age, coverage), and hard limits (no full addresses, no per-account liquidation prices). It omits only error/failure behavior for unknown tickers.

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-loaded with the question and the returned fields, then the tier caveats. It is a single dense paragraph that is a touch long because it enumerates four paid route paths (/v1/lite, /v1/coin, /v1/scan, /v1/wallet) that are not invocable here, which is mild noise but does set expectations about data gaps.

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 one parameter, no output schema and no siblings, the description carries the return-value burden itself and does so: bias level, cohort long-vs-short counts, snapshot age, and coverage. An agent can decide and call correctly without further information.

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 single `symbol` parameter already carries example tickers and accepted alternate formats (BTC-PERP, ETH-USD, SOLUSDT). The description only restates that it takes a Hyperliquid perp ticker, adding no syntax or validation detail beyond the schema, so 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?

Opens with a concrete question the tool answers ("Is the smart money long or short this coin?") and names the specific verb+resource: returns cohort positioning for a Hyperliquid perp ticker. It enumerates the exact return categories (strong long / lean long / mixed / lean short / strong short) so an agent knows precisely what comes back.

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?

Scopes the tool to Hyperliquid perp tickers and labels it a "free preview tier," explicitly contrasting it with paid x402 routes that add notional, flows, leverage and positions. That tells the agent when this tool's answer is sufficient versus when richer data is required, though it gives no explicit when-not condition (it is the only sibling).

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