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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds that the tool returns a 'snapshot' (implying a point-in-time view) and lists the contents, which is useful beyond the annotations. It does not discuss data freshness (the schema's 'full' detail mentions 'data age'), rate limits, or pagination, so it's adequate but not rich.

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?

Two sentences: the first is a long but front-loaded enumeration of returned data, the second gives usage scenarios. No redundant fluff, though the list of metrics is dense; still efficient and well-organized.

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, zero-required-parameter screener with a fully documented schema and annotations, the description is nearly complete: it tells the agent what data is returned and when to use it. A minor gap is the absence of any mention of the two optional parameters or the 'brief' vs 'full' output difference, but the schema already covers those, so this is sufficient.

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 enum descriptions for both parameters, so the schema already fully documents them. The description does not mention 'detail' or 'sort_by' at all, adding no parameter information. Baseline 3 is appropriate when the schema carries the parameter burden.

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 specifies a clear verb and resource ('Returns a snapshot of the Hyperliquid perpetual market') and enumerates the exact metrics returned (open interest, volume, breadth, funding, top lists, gainers/losers). It distinguishes itself from siblings like get_funding_rates and get_orderflow_snapshot by covering aggregate market-wide statistics rather than a single metric.

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?

It explicitly states when to use it: 'Use it for market overviews, top movers or the most active markets.' This gives concrete scenarios and implicitly excludes narrower siblings that focus on one dimension (funding, orderflow, liquidation, whale positioning). No alternatives are named, but the intended use is unambiguous.

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