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

With no annotations at all, the description carries the full burden and does well: it discloses the paid cost and accepted payment rails (USDC on Base or Solana), that no account or API key is needed, that failed calls are not charged, and that data is live DefiLlama-sourced. It stops short of pagination behavior, rate limits, or latency expectations.

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 'Paid.', then purpose, then pricing, then endpoint URL, in a compact block with no filler. The telegraphic sentence fragments read slightly clipped but every clause carries information.

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 tool with no output schema and no annotations, the description covers the returned metrics, the data source, the cost and the access model. What remains thin is the response shape (units, whether rows are per-pool per-chain) and result pagination.

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% and all three optional parameters (sort, limit, min_tvl_usd) are documented with defaults and value ranges in the schema itself. The description adds nothing about them, so the baseline 3 applies; it does at least confirm which fields the rows contain.

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 scope: aave-v3 pools across all chains, returning APY, TVL and 7d APY change. This implicitly separates it from the chain-, token- and stablecoin-scoped yield siblings, but the description never names or contrasts those alternatives 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?

Usage is only implied by the protocol scope; there is no explicit when-to-use guidance or routing statement such as 'use buy_yields_chain_ethereum for a single chain' or 'use buy_yields_protocol_aave-v4 for v4'. The payment and access notes ($0.01 USDC, no account, no API key) are useful context but are not selection guidance.

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