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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description adds useful behavior: only "active" markets are included, the response is a top-N ranking (default 25, unless limit is set), and funding is hourly with the sign convention defined in the schema. It does not mention whether values are snapshot-at-call or delayed, but for a read-only snapshot tool the disclosure is solid.

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 sentences: what it returns, how to rank it, how to filter, plus the default cardinality — front-loaded with zero filler. Every clause carries actionable information.

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 an output schema present, return-field documentation is not required; coverage of the six optional params, the default size, and the active-market scope is enough for an agent to call it correctly on the first try.

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 description coverage is 100%, and the schema already documents defaults (limit 25, sort_by volume), the enum values, and the funding sign convention. The description restates the default top-25 behavior and the min_volume_usd intent without adding syntax or edge-case detail the schema lacks, so 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?

It names a specific verb and resource ("Active Hyperliquid markets ranked in one call") and enumerates the returned metrics — mark price, 24h change/volume, open interest, hourly funding — which differentiates it from the single-metric siblings (get_mark_prices, get_open_interest, get_funding_rates). It stops short of explicitly naming those alternatives, so the composite-vs-single-metric distinction must be inferred.

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?

"Sort by abs_funding for the most extreme funding, abs_change_24h for the biggest movers" ties each sort key to a concrete analyst intent, and "Use min_volume_usd to skip illiquid markets" states when a filter is warranted. There is no explicit when-not-to-use or pointer to a sibling for narrower queries (e.g. a single price), so it falls short of full routing guidance.

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