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

No annotations exist, so the description carries the full behavior burden and does meaningfully: it discloses the $0.01 USDC cost on Base or Solana, that no account or API key is needed, and that failed calls are not charged — all decision-critical for a paid tool. It stops short of rate limits, latency, or response shape, which keeps it from 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?

One front-loaded sentence covers what the data is and its fields, a second covers pricing and access, and the URL is appended last. Nothing is repeated and every clause carries distinct 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?

With three optional, fully documented parameters, no nested objects, and no output schema, the agent needs to know cost, payment method, data provenance, and returned fields — all are present. Additional return-value detail is unnecessary without an output 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 description coverage is 100% (sort, limit, min_tvl_usd all documented with defaults and ranges), so the baseline is 3. The description's 'top pools by TVL or APY' only echoes the sort parameter and adds no unit, format, or edge-case detail beyond the schema.

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 on Monad') plus scope ('top pools by TVL or APY') and the returned fields (base/reward APY, TVL, 7d APY change). The chain-specific naming and DefiLlama source let an agent separate it from the many buy_yields_protocol_* and buy_tvl_* siblings 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?

The description makes clear this is a paid endpoint with a stated price and payment rails, which informs the decision to call it, but it never names an alternative or states when to prefer it over e.g. buy_tvl_monad or a protocol-level yields tool. Usage is implied by the chain scope rather than explicitly routed.

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