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

With no annotations provided, the description carries the full burden and does well: it discloses that the call is paid ($0.002 USDC on Base or Solana), requires no account or API key, is not charged on failure, and that the underlying data is DefiLlama. That is exactly the kind of pre-call context an agent needs before spending money. It stops short of rate limits, response shape and how large the pool list typically is.

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?

Opening with 'Paid.' front-loads the most decision-relevant fact, and the content is delivered in a few compact clauses with no filler. It is telegraphic to the point of being clipped, and the trailing raw endpoint URL is marginal value for an agent that cannot call it directly.

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?

The tool is a read-only paid data fetch with three optional parameters and no output schema, so the description needs to say what comes back and what it costs — it does both (APY, TVL, 7d APY change; $0.002 USDC, not charged on failure). What remains uncovered is volume of results and how the returned pool rows are keyed, which is minor here.

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% and all three parameters (sort, limit, min_tvl_usd) already carry their allowed values and defaults in the schema, so the baseline is 3. The description adds nothing about parameter behavior — for example whether min_tvl_usd applies per chain or globally — so it neither compensates nor detracts.

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 and scope: live DeFi yields for the jpool protocol, its pools across chains, with APY, TVL and 7d APY change. The protocol name in the description matches the tool name, which is what separates it from the ~200 sibling buy_yields_protocol_* tools. It does not, however, say how it differs from buy_yields_chain_* or the similarly named jagpool protocol, so the differentiation is implied rather than stated.

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 implied by the protocol name — call this to get yield data for jpool pools — but there is no explicit when-to-use statement, no exclusion of the chain-level or token-level yield siblings, and no guidance on when to prefer those alternatives. The payment and access notes are about cost, not about tool selection.

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