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

With no annotations, the description carries the full disclosure burden and does so well for a paid tool: it declares the price, accepted payment chains, that no credentials are needed, and that failed calls are not charged — exactly the facts an agent needs before spending money. It leaves out rate limits, response shape, and caching/refresh cadence, which keeps it short of a 5.

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?

Front-loaded with the single most decision-relevant word ("Paid"), then purpose, then cost and access terms, then the endpoint URL. Every sentence carries distinct information; the URL is arguably redundant but still operationally useful. No filler or repetition.

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 no-required-parameter read tool with no output schema and no annotations, the description covers purpose, data content, source, pricing, and access requirements. An agent could invoke it correctly without further information; only return-format and rate-limit details are absent, and those are less critical for a simple list endpoint.

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 all three parameters (sort, limit, min_tvl_usd) carry inline descriptions with defaults, so the schema does the semantic work. The description mentions APY and TVL only as output fields, not as parameters, so it adds no parameter meaning beyond the schema — baseline 3 is appropriate.

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 (live DeFi yields for the hyperliquid-hlp protocol), its scope (pools across chains), and the exact data fields returned (APY, TVL, 7d APY change, DefiLlama as source). The protocol name in the description matches the tool suffix, so an agent can distinguish it from the hundreds of sibling buy_yields_protocol_* and buy_yields_chain_* tools.

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?

The description conveys operational context (paid, $0.01 USDC on Base or Solana, no account or API key, failures not charged), which helps an agent decide it can actually be invoked. It does not, however, say when to pick this over buy_yields_chain_hyperliquid-l1, buy_yields_token_hype, or buy_yields_top, nor any exclusion conditions — so usage guidance is implied by naming rather than stated.

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