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 the cost ($0.002 USDC), accepted payment chains, that no auth/API key is needed, and that failed calls are not charged. It omits response shape, rate limits, and pagination behavior, which keeps it short of a 5.

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 'Paid' and the core purpose, then packs pricing, auth, and billing behavior into a couple of sentences with no filler. The trailing raw URL is slightly redundant given the tool is already addressable.

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 no-param-required read tool with no output schema, the description covers what is returned (APY, TVL, 7d APY change), the data source, and the cost/auth model. Only edge behavior such as error semantics or row shape beyond the named metrics is unstated.

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 schema already documents sort, limit, and min_tvl_usd with defaults and ranges. The description adds nothing about parameter usage, 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 yields for uniswap-v4: its pools across chains with APY, TVL, 7d APY change') and names the data source. An agent can tell it apart from buy_yields_protocol_uniswap-v3 or buy_yields_chain_* without opening a schema.

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?

It gives the commercial/precondition context (paid, $0.002 USDC on Base or Solana, no account, no API key) which helps an agent decide it can call it. However, it never says when to prefer this protocol-level tool over the chain-level or sibling protocol yield tools, so routing is left implicit.

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