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

With no annotations, the description carries the behavioral load and does well: it discloses pricing ($0.005 USDC on Base or Solana), that no account or API key is required, and that failed calls are not charged. It does not mention rate limits or response shape, so it stops short of full transparency.

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?

The definition is compact and front-loaded: what the tool returns first, then cost, payment rails, access requirements, billing behavior, and endpoint. Every clause carries information an agent or caller needs.

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 exists, but the description enumerates the returned fields (APY, TVL, 7d APY change) and its data source, which is sufficient for a simple filtered-list tool. The absence of annotation coverage is largely offset by the pricing and payment disclosures.

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 the three parameters (sort, limit, min_tvl_usd) are already documented, and the description adds no syntax or default detail beyond them. Baseline 3 applies when the schema does the work.

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 and scope: live DeFi yields for the usd-ai token, pools across chains, with APY, TVL and 7d APY change from DefiLlama. An agent can distinguish this from the buy_yields_chain_* and buy_yields_token_* siblings by the protocol-specific scope, though the description never explicitly contrasts them.

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 data described (pool yields for one protocol across chains), but there is no explicit when-to-use or when-not-to-use statement, and no pointer to the chain- or token-scoped siblings an agent might choose instead.

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