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

With no annotations, the description carries the full behavioral burden and does a solid job: it discloses the price and payment chains ($0.005 USDC on Base or Solana), that no account or API key is needed, that failed calls are not charged, and that data comes from DefiLlama. It omits rate limits and response-size or pagination behavior.

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-loads 'Paid.' and then the payload, price, access conditions and endpoint in roughly priority order with no filler. The colon-spliced phrasing ('jupiter-lend: its pools across chains') reads slightly fragmented but costs no extra length.

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 simple three-optional-filter read tool with no output schema and no annotations, the description covers what is returned (APY, TVL, 7d change), provenance (DefiLlama) and the payment model. The main gap is that return shape and pagination behavior are undescribed, but the field list partially compensates.

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?

All three parameters already have schema descriptions at 100% coverage (sort, limit, min_tvl_usd with defaults), so the schema does the heavy lifting. The description adds nothing about sorting semantics, default TVL threshold rationale, or how limit interacts with the min_tvl filter, so 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 verb and resource: returns live DeFi yield pools for the jupiter-lend protocol, with APY, TVL and 7d APY change. The protocol scoping ('its pools across chains') distinguishes it from the chain- and token-scoped siblings, though it never names those alternative tools 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 by the protocol scoping and by the access terms (paid, no account, no API key), but there is no explicit statement of when to pick this over buy_yields_chain_solana, buy_yields_token_jupsol, or other buy_yields_protocol_* tools. The agent must infer routing from the tool name alone.

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