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

No annotations exist, so the description carries the full burden, and it does well: it discloses the paid cost ($0.002 USDC on Base or Solana), that no account or API key is needed, and that failed calls are not charged — real behavioral facts an agent needs before spending money. It does not describe the response shape or result ordering, which keeps it below 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?

Dense and front-loaded: payment model first, then what the data is, then cost/access terms, then the endpoint URL. Every clause carries information; the bare 'URL ...' fragment is the only slightly awkward element.

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 tool with a fully documented schema and no output schema, the description supplies purpose, data provenance, price, payment chain, credential requirements, and failure billing. Nothing an agent needs to call it correctly is missing.

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 inline with defaults), so the schema does the heavy lifting. The description adds no parameter detail beyond noting that pools span all chains — it does not explain that there is deliberately no chain filter, which would have been the one genuinely additive point.

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 concrete resource and verb: 'Live DeFi yields for curvance: its pools across chains with APY, TVL, 7d APY change', plus the upstream data source (DefiLlama). An agent can tell this is the per-protocol curvance variant rather than a chain- or token-scoped yield tool, though it never explicitly names those siblings.

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 scope ('its pools across chains') but there is no explicit when-to-use or when-to-prefer-an-alternative statement against the many sibling yield tools (buy_yields_chain_*, buy_yields_token_*, buy_yields_stablecoins). The payment and access notes help the agent decide it *can* call it, not *should*.

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