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

With no annotations, the description carries the full burden and does disclose the costly parts: explicit per-call price, accepted payment chains, no credential requirement, and that failed calls are not charged (a useful retry-safety signal). It omits rate limits or freshness/refresh cadence of the DefiLlama data, which matters for a paid data endpoint.

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?

It is a compact block with the key idea ('Paid' + what data) front-loaded, followed by price, access model, and endpoint URL. Every clause carries information; the URL is arguably redundant with the tool's own configuration but harmless.

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 zero-required-parameter read endpoint with no output schema, the description covers cost, payment rails, data source, and the fields returned (APY, TVL, 7d change), which is enough to call it and interpret results. Only data freshness and pagination behavior are unaddressed.

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 sort, limit, and min_tvl_usd each documented including defaults. The description adds no syntax, units, or interaction detail beyond the schema, so the baseline of 3 is appropriate.

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?

The description names a specific resource and scope: yield pools for the plume-vaults protocol across chains, returning APY, TVL, and 7d APY change from DefiLlama. That separates it from the chain-scoped siblings such as buy_yields_chain_plume-mainnet, but no sibling is named and the distinction from buy_yields_top or buy_yields_stablecoins is left implicit.

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 real prerequisites (paid, $0.01 USDC on Base or Solana, no account or API key) which effectively tell the agent this is a lightweight read. However, it never says when to pick this protocol endpoint over the chain-level or top-yields endpoints, so the routing decision is only implied by the protocol name embedded in the tool name.

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