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

With no annotations, the description carries the full burden. It usefully discloses the payment model ($0.008 USDC per call, paid with x402 on Base), which is important behavioral context, but says nothing about data freshness, rate limits, or failure behavior. It adds real value on cost but leaves other operational traits uncovered.

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 short sentences, front-loaded with the core purpose and followed by the cost. Every clause carries information, and nothing is redundant.

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 one-parameter, read-only summary tool with no output schema, the description names the key returned metrics and the pricing model, which is enough to call it correctly. Minor gaps remain around data currency and response format, but nothing essential 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% and the single parameter is already documented there. The description only restates that a chain can be named or omitted for the top 25 chains, adding no syntax, naming conventions, or examples beyond the schema. Baseline 3 applies.

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+resource: a per-chain DeFi yield overview with named outputs (TVL-weighted median stablecoin APY, top 5 projects by TVL and pool counts). It is clear what it returns, though it does not explicitly distinguish itself from siblings like defi_yields or defi_defi_tvl.

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 explains the chain parameter's scope ('for one chain or the top 25 chains') but gives no guidance on when to choose this tool over defi_yields, defi_defi_tvl, or yields_curve. No when-to-use or when-not-to-use guidance is present.

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