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

No annotations exist, so the description carries the full burden and does substantial work: it discloses that the call is paid, the exact price ($0.005 USDC), accepted payment chains (Base or Solana), that no account or API key is needed, that failed calls are not charged, and the underlying data source (DefiLlama). It stops short of stating rate limits or latency, but the commercially relevant behavior is covered.

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 the key constraint ('Paid') and then packs purpose, data fields, price, payment options, auth model, and billing policy into a few dense fragments with no filler. The telegraphic style is terse but every clause carries distinct information.

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?

With no annotations and no output schema, the description supplies the missing safety and billing context plus the shape of the returned data, which is enough to decide whether to call it. It could be slightly more complete by hinting at response pagination or how multi-chain pools are grouped, but nothing essential is absent.

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%, with sort, limit, and min_tvl_usd all documented including defaults, so the schema does the heavy lifting. The description adds no parameter-level meaning beyond what the schema already provides, which is the baseline 3 case.

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 — live DeFi yields for aave-v4 pools across chains — and enumerates the returned fields (APY, TVL, 7d APY change). Combined with the protocol-specific tool name, an agent can distinguish it from the many buy_yields_chain_*, buy_yields_token_*, and buy_yields_protocol_aave-v3 siblings.

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 makes the scope clear (one protocol, all its pools across chains), which implies when to pick it over chain- or token-level siblings, but it never explicitly names an alternative or says when NOT to use it. With hundreds of near-identical siblings in the namespace, one routing sentence would materially help.

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