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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: it is sourced from Hyperliquid's public info API, covers 190+ contracts, includes delisted status, and can be filtered to one symbol. It does not discuss rate limits or error behavior, but those gaps are modest given the annotations.

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 description is front-loaded with the core purpose, then proceeds to fields, usage, and the optional filter. Every sentence contributes operational value: what the data is, why it matters before market-data calls, and how to request a single symbol.

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 one-parameter read-only metadata tool with annotations covering safety and an output schema present, the description is complete. It tells the agent what the tool returns at a high level and exactly how it fits into the symbol-resolution workflow.

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 single optional coin parameter is already documented in the schema with an example. The description reinforces that passing coin returns one symbol instead of the full list, but adds little semantic detail beyond the schema. Baseline 3 is appropriate when the schema fully carries parameter meaning.

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 resource and scope: perpetuals universe metadata from Hyperliquid, every listed perp contract with fields like szDecimals, maxLeverage, and isDelisted. It distinguishes the perp universe from spot context by naming the perp list explicitly and by tying it to perp market-data siblings.

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?

Explicitly tells the agent when to use it: to resolve a human-asked symbol to a Hyperliquid contract before calling hyperliquid_mids, hyperliquid_l2_book, hyperliquid_candles, or hyperliquid_funding_history. It also gives the key usage constraint that those tools require the bare coin symbol shown here, not a suffixed pair name.

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