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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so safety and idempotency are covered structurally. The description adds the metrics returned (mark/oracle, funding periods, OI, volume), which is mildly useful context, but since an output schema exists and nothing is said about rate limits, delisted-market semantics, or pagination behavior beyond the flag, the incremental disclosure is modest.

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, front-loaded with the resource and returned metrics, then the invocation context and capabilities. No filler; every clause carries 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 handling return shape and only optional params, the description is nearly complete for correct invocation. The notable gaps are the HIP-3 dex option and delisted-market handling, which an agent would only learn from the schema.

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 67% and the description only broadly gestures at 'name filter, sorting, and pagination', mapping loosely to filter, sort, limit, and offset. It says nothing about the dex (HIP-3) parameter or includeDelisted, both of which are documented in the schema, so the description adds little beyond structured fields.

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 verb and resource (list Hyperliquid perpetual markets) and enumerates the data returned: mark/oracle price, hourly and annualized funding, open interest, 24h volume. That level of detail lets an agent distinguish it from siblings like hl_funding_screener or hl_orderbook without opening the schema.

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 to discover valid coin symbols and scan the board' gives a clear purpose context for invocation. It does not name alternatives or exclusions (e.g., when to prefer hl_funding_screener for funding-only screening), so it falls short of explicit when/when-not guidance.

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