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

With no annotations, the description carries the full burden and does a good job: it discloses the $0.005 USDC price on Base or Solana, that no account or API key is needed, and that failed calls are not charged. It stops short of rate limits, pagination behavior, or the exact response shape beyond the three listed fields.

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 payment notice, then the purpose, then pricing/auth terms and the endpoint URL in compact sentences with little waste. The URL partly duplicates the tool name but is useful for verification.

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?

Three optional params, no output schema, and no annotations, yet the description covers cost, auth model, failure billing policy, data source, and returned fields. Only sort/limit/min_tvl behavior and rate-limit details are left to the schema.

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 coverage is 100%, so sort, limit, and min_tvl_usd are already documented with defaults in the schema. The description's mention of APY, TVL, and 7d APY change loosely maps to the sort options but adds no new syntax or format detail, 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 verb and resource: live DeFi yield pools for the Concentrator protocol across chains, with named fields (APY, TVL, 7d APY change) and the data source (DefiLlama). The protocol scoping implicitly separates it from the buy_yields_chain_* and buy_yields_token_* siblings, but no sibling is named 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?

The description makes clear what data is served, so a reader can infer it applies when Concentrator-protocol yields are wanted, but it never states when to prefer a chain-level, token-level, or top-yields sibling instead. No prerequisites or exclusion conditions are given beyond the implied protocol filter.

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