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

With no annotations, the description carries the full burden and does well: it discloses paid access ($0.01 USDC on Base or Solana), no account or API key requirement, and that failed calls are not charged. It omits nothing critical for invoking it, though pagination/response-size behavior is unstated.

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-loaded with the core resource and data scope, followed by pricing and access terms. The telegraphic fragment style is efficient but slightly choppy, and the raw URL is useful but reads as boilerplate.

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?

There is no output schema, so the description must convey what comes back; it does by naming live pools, APY, and TVL with a data source. Combined with the pricing and access model, an agent has enough to decide and pay, with only output shape/pagination left implicit.

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 defaults documented for sort, limit, and min_tvl_usd. The description adds no filtering semantics beyond the schema, 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 pools holding USDS across protocols and chains, APY and TVL (DefiLlama data)'. The token scoping implicitly separates it from the many sibling buy_yields_token_* tools, but it never names an alternative, so differentiation relies on the tool name.

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 implied by the data offered (yield opportunities on USDS) and the payment/access terms make the commercial context clear. However, there is no explicit 'use this when...' guidance and no mention of when to prefer buy_yields_chain_*, buy_yields_protocol_*, or buy_yields_stablecoins siblings instead.

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