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

With no annotations, the description carries the load and does so well: it discloses the paid model ($0.005 USDC on Base or Solana), that no account or API key is needed, that failed calls are not charged, and where the data originates. It stops short of rate limits, latency, or how payment is attached to the request, so not 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?

Three tight sentences: cost/access first, then what the data is, then payment mechanics and endpoint. Every clause carries distinct information and nothing is repeated.

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?

No output schema and no annotations, so the description must convey both result shape and cost — and it names the returned metrics and the price model. Missing only peripheral detail such as response envelope, pagination, or error semantics beyond 'failed calls not charged'.

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 100%, so sort, limit, and min_tvl_usd are already documented by the schema. The description restates that results can be ordered by TVL or APY but adds no extra meaning (no unit guidance, no interaction between sort and min_tvl_usd), so the baseline 3 applies.

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: live DeFi yield pools on Linea, ranked by TVL or APY, with the fields returned (base/reward APY, TVL, 7d change) and the data source (DefiLlama). The chain scoping implicitly separates it from the many sibling buy_yields_chain_* tools, but it never names a sibling or contrasts with buy_tvl_linea or buy_yields_protocol_*.

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 only implied by the word 'top' plus the sort options, so an agent can infer it is for pool discovery/ranking on Linea. There is no explicit when-to-use guidance, no exclusion such as 'for a single protocol use buy_yields_protocol_*' or 'for chain-level TVL use buy_tvl_linea', and no prerequisites beyond the payment note.

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