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 most decision-relevant trait: this is a paid call at $0.003 USDC via x402 on Base, which affects whether the agent should invoke it. It also enumerates the risk flags returned (APY spike, reward-heavy, IL, low TVL, multi-asset exposure), which tells the agent what judgment the tool performs. It omits rate limits, failure modes, and whether ranking is by risk-adjusted APY or raw APY.

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?

Two dense sentences: capability plus filters first, output contents second, commercial terms last. No filler, nothing repeated, and the front-loaded clause tells the agent immediately what it ranks.

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 no output schema and no annotations, the description must convey both behavior and return shape, and it does explain the returned APY and risk flags plus the payment requirement. The gaps are modest: it does not state sort order, whether results are paginated beyond 'limit', or what an empty result means.

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 every parameter is already documented with examples and defaults (USDC/ETH, Ethereum/Base, 1-50 default 20, TVL default 1000000). The description restates the same filters without adding format, precedence, or combination rules. Baseline 3 is appropriate since the schema does the work.

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 action: ranked DeFi yields with named filters (asset, chain, min TVL, stablecoin-only, single-sided) and a described output shape (risk-adjusted APY plus risk flags). That is well beyond a tautology. It does not name or differentiate itself from the adjacent defi_pool / defi_summary siblings, which keeps it at 4.

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 filters imply when the tool is useful (screening pools by safety/liquidity traits), but there is no explicit when-to-use or when-not-to-use statement. Crucially, it never says how it differs from defi_pool or defi_summary, so an agent facing three DeFi tools must guess. Usage is only inferred from the description.

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