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

With no annotations at all, the description carries the burden and does real work: it discloses that calls are paid ($0.005 USDC on Base or Solana), require no account or API key, and are not charged on failure, plus that data is live DefiLlama-sourced. It stops short of explaining rate limits or the payment mechanism itself, but the auth and billing profile is unusually well 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 paid flag, then purpose, then price, terms, and endpoint URL. Dense but every clause is functional; the raw URL at the end is the only element that reads as boilerplate rather than agent-facing guidance.

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?

For a three-optional-parameter read query with full schema coverage and no output schema, the description covers scope, data source, cost, and failure policy. What is missing is response shape and how payment is actually transacted, both of which an agent would need before committing to a paid call.

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 spelled out for sort, limit, and min_tvl_usd, so the schema does the work. The description adds no syntax or interpretation beyond it, which is the expected baseline here.

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: where to earn yield on CRVUSD, listing live pools across protocols and chains with APY and TVL. That is concrete enough to distinguish it from the chain-level (buy_yields_chain_*) and protocol-level (buy_yields_protocol_crvusd) siblings, though it never names them 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 implies the use case (find yield opportunities on CRVUSD) but gives no explicit when-to-use or when-not guidance, and does not route the agent between this tool and buy_yields_stable_crvusd or buy_yields_protocol_crvusd. Usage is inferable from the scope wording, not stated.

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