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

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint), so the bar is lower. The description adds genuinely useful behavioral context beyond them: it discloses the temporal caveat that only retrieval time is returned and the exchange observation time is unknown, and it sets expectations with "Not a prediction."

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?

Three short sentences, led by the "Use for..." trigger, with each sentence earning its place (capability list, stock-quote disambiguation, temporal caveat/expectation). The "Not a prediction" fragment is terse but purposeful; no filler.

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 double duty and reasonably lists the returned fields plus the retrieval-time caveat for a simple single-parameter read tool. The main remaining hole is the asset-identifier format and behavior for an unknown asset, neither of which is addressed.

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?

There is one parameter (asset) with 0% schema description coverage, so the description carries the full burden. It never explains the asset identifier format, examples, casing, or naming convention, and the existence of a resolve_hyperliquid_market sibling suggests asset resolution is non-trivial. The only hint is the implied 'market' phrasing.

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 description gives a specific resource and enumerates the exact fields returned (mark price, 24h change, funding, open interest, volume), and explicitly contrasts it with a US stock quote to separate it from the financial-data siblings. It does not explicitly route the agent to the adjacent Hyperliquid siblings (e.g. resolve_hyperliquid_market), so sibling differentiation is only partial.

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?

"Use for a Hyperliquid market..." supplies a clear trigger condition, and "not a US stock quote" acts as a mild exclusion against the stock tool family. However, there is no guidance on when to prefer the many nearby Hyperliquid siblings, nor any prerequisite or when-not statement beyond the stock contrast.

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