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

Annotations already cover read-only and open-world scope, so the description earns credit for adding genuinely new behavior: a $0.002 USDC cost per successful call via x402 on Base/Solana/Arc, and explicitly that failed calls are not charged. That billing/failure semantics is not derivable from annotations and materially affects an agent's willingness to call. It stops short of 5 only because no rate limits or failure modes are described.

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 primary purpose and return contents, followed by the safety disclaimer and pricing. Every sentence carries information, though the 'Information only, not financial advice' clause is boilerplate that slightly dilutes an otherwise dense definition.

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 the description need not explain return structure, yet it helpfully summarizes the payload anyway. Combined with annotations covering safety and the description covering cost, an agent has what it needs to call this correctly; only the ambiguity about what counts as a valid Hyperliquid address is unaddressed.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents the 0x address format. The description adds the phrase 'by address' but no additional semantics such as chain scope or expected address type beyond what the schema states, making this the baseline case.

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 (a Hyperliquid account retrieved by address) and enumerates the exact returned content: account value, margin used, withdrawable amount, and per-position side/size/entry/mark price/unrealised PnL/leverage/liquidation price. This is unambiguous against siblings such as perps_markets (market data) or evm_wallet (generic balances).

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?

Implicitly guides usage via the read-only framing and the field list, but never states when to choose this over perps_markets, evm_wallet, or solana_account, nor any precondition (e.g. address must be a Hyperliquid account, not just any 0x address). The context is inferable but not spelled out.

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