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

With no annotations, the description does meaningful work: it discloses that the call is paid ($0.01 USDC on Base or Solana), requires no account or API key, uses DefiLlama as the data source, and that failed calls are not charged. That billing/error policy is exactly the kind of behavior an agent needs before spending money, though the response row format and pagination behavior are not described.

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?

Every sentence earns its place: payment model, data scope, cost, auth requirements, billing on failure, and endpoint URL, all front-loaded with 'Paid.' so the agent sees the cost constraint first. No filler.

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 carries the full burden and largely meets it by listing the returned fields, the data source, and the payment mechanics. The remaining gap is the actual response envelope/row shape, which an agent must discover at call time.

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%, so sort, limit, and min_tvl_usd are already documented in the schema. The description adds no additional meaning about their interaction or defaults, 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?

The description names a specific resource (centrifuge-protocol pools) and the verb (fetch live DeFi yields), plus the exact fields returned: APY, TVL, 7d APY change. The phrase 'its pools across chains' distinguishes it from the chain-level siblings, though it never explicitly names those alternatives.

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: an agent can infer this is the per-protocol view rather than the per-chain or per-token views. There is no explicit when-to-use/when-not-to-use guidance and no mention of how to choose between this and buy_yields_top or buy_yields_chain_*, leaving routing to the agent's inference.

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