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

Annotations already declare readOnly/idempotent/openWorld, and the description adds real context beyond them: the exact cohort definition (top 100 by 30-day PnL, ≥ $5M volume, positive ROI) and a per-call cost of $0.002. It doesn't cover refresh cadence or what happens when a coin isn't tracked, so it falls short of a 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?

The cohort definition leads, followed by output fields, price, and the sibling alternative — logically ordered with no filler sentences. The long enumeration of return fields is justified by the absence of an output schema, though it makes the block dense to parse in one pass.

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 does the necessary work of enumerating return fields (smart, smart_long_share_pct vs all_tracked_long_share_pct, flow with largest moves), plus cohort and cost. Minor gaps remain around error behavior for untracked coins and data freshness, which an agent would want before spending $0.002.

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 both parameters documented (coin = main-dex coin, hours = lookback default 24), so the baseline applies. The description reinforces that hours is the window for the flow block ('flow {hours, ...}'), but adds no new syntax or constraint meaning.

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 (positioning of the top-100 30-day-PnL Hyperliquid accounts) in a specific scope (one coin), and names the sibling it is not (hl_smart_flow, all coins). An agent can distinguish it from hl_smart_flow and whale_moves without opening any 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?

Explicitly says what to use it for ('how top-PnL Hyperliquid traders are positioned in one coin') and names the alternative with its selecting condition ('for all coins use hl_smart_flow'). No inference required.

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