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

With no annotations, the description carries the full burden. It usefully enumerates the returned summary (current rate, mean, annualized mean, min/max, share of positive periods, drift direction) and adds the domain fact that funding is paid hourly, but says nothing about auth, rate limits, or read-only nature.

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 tight sentences with the return payload front-loaded. The only waste is the redundant 'x402-hyperliquid-funding:' prefix that merely restates the tool name.

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?

Return-value content is well covered despite there being no output schema, and the hourly-funding domain context is a nice addition. The input side, however, is entirely unaddressed for a 4-parameter tool with zero schema descriptions.

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 0% and the description mentions no parameter names at all. It never explains the distinction between the redundant-looking coin/symbol pair or between hours and limit, leaving four undocumented string parameters to be guessed at.

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: Hyperliquid funding-rate history for one perpetual, plus the summary fields returned. It implicitly separates itself from x402-hyperliquid-predicted-funding (history vs prediction) and the generic x402-funding-rate, but never names an alternative explicitly.

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 context is implied rather than stated: 'the number that decides whether a position is worth keeping' frames it for carry-trade evaluation. There is no explicit when-to-use, when-not-to-use, or named alternative among the many funding-related siblings (x402-funding-rate, x402-hyperliquid-predicted-funding, x402-perp-funding-arb).

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