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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower, and the description still adds real value: source of data (Hyperliquid public market data), rate limits (30 calls/day per IP), the paid path via x402/credits, and the failure-refund behavior. That is exactly the kind of auth/quota context annotations cannot express, though the payment paragraphs read as hub boilerplate shared across tools.

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 functional content is front-loaded in a single efficient sentence, which is good. However, roughly two-thirds of the text is pricing/payment boilerplate about the hub's billing mechanics rather than about what the tool does, which dilutes the signal for an agent trying to decide whether to call it.

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?

For a read-only snapshot tool with no output schema, the description names the returned fields (price, 24h change, 24h volume, open interest, funding) and the data source, which is enough for an agent to know what comes back. Exact response field names are unspecified, but that is a minor gap given the documented field list.

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 both parameters are documented in-schema, including the enum for tier and the accepted ticker forms, so the schema does the heavy lifting. The description echoes the 20-symbol cap and the 'BTC,ETH,SOL' example already present in the schema but adds no format detail beyond it; 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?

The first sentence states a specific verb+resource (current USD price of up to 20 coins) and enumerates the returned fields (24h change, volume, open interest, funding), plus names the data source (Hyperliquid). It implicitly separates itself from token-security siblings like check_token, though it never explicitly contrasts with close siblings such as crypto_movers or check_perp_order.

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?

Usage is only implied: an agent can infer 'use this to get a live quote' but there is no explicit when-to-use vs. when-to-use-something-else guidance. Nothing tells the agent whether to prefer crypto_movers for movers or check_perp_order for perp-specific data, so the sibling boundary is left to inference.

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