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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description goes beyond them by disclosing the hourly sampling interval and decoding the sign convention (positive = longs pay shorts), which an agent cannot infer from the annotations and would otherwise likely get wrong. It stops short of covering pagination or limit behavior, but that is minor here.

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 short sentences with zero filler, and the resource definition is front-loaded before the interpretive note. Nothing is repeated from the schema or annotations.

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?

An output schema exists, so return shape need not be described, and the description covers granularity, market scope, and the sign semantics an agent needs to interpret results. A pointer to get_funding_stats for aggregate vs. historical statistics is the only notable omission.

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 both parameters are documented there, including market name formats, so the baseline of 3 applies. The description adds no syntax or default detail beyond the schema; the HIP-3 mention lightly signals supported market families but does not explain parameter usage.

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+resource ("Hourly funding rate history") and scopes it to Hyperliquid perps, explicitly including HIP-3 builder perps. It does not name the closely related siblings (get_funding_stats, get_user_funding), so an agent must infer the split from the name alone.

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?

Usage is implied by the word "history" and the hourly granularity, but there is no explicit statement of when to pick this over get_funding_stats or get_user_funding, and no exclusions or prerequisites. An agent can guess the intent but receives no routing help.

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