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

With no annotations, the description carries the full burden and does well: it discloses that the call is paid ($0.002 USDC on Base or Solana), that no account or API key is required, that failed calls are not charged, and that the data originates from DefiLlama. It stops short of disclosing rate limits, caching/freshness windows, or what an empty result looks like.

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?

Four short sentences, front-loaded with what the tool returns, then commercial terms, then the endpoint. Every sentence carries distinct information an agent needs before spending money; 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 paid read endpoint with no output schema and no annotations, the description supplies resource scope, returned metrics, cost, payment chains, auth requirements, and failure charging — enough to call it correctly and know the price. It only lacks return-shape detail (field names, pagination/row semantics beyond the limit param) and any freshness or rate-limit note.

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, so the baseline applies. The description adds no parameter-level meaning (e.g., whether min_tvl_usd filters before or after limit), 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?

Names a specific resource (live DeFi yield pools for the mezo-earn protocol across chains) and enumerates the returned metrics: APY, TVL, 7d APY change, sourced from DefiLlama. The protocol name in the tool name plus 'its pools across chains' separates it from chain-level and token-level yield siblings implicitly, but the description never explicitly contrasts with buy_yields_chain_mezo or buy_yields_top.

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 resource scope (protocol-level yield data for mezo-earn), but there is no explicit statement of when to choose this over the chain or token yield siblings, nor any exclusion, prerequisite, or freshness caveat beyond the word 'Live'. The payment and access notes describe logistics rather than selection guidance.

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