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

With no annotations, the description carries the behavioral burden and does well: paid ($0.01 USDC on Base or Solana), no account or API key, and failed calls are not charged — all material for an agent deciding whether to call. It stops short of describing the response shape or pagination behavior, which matters since no output schema exists.

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 but front-loaded: 'Paid.' leads, then what the data is, then cost/access terms. The endpoint URL is arguably redundant for an agent that already has the tool, but nothing else is wasted.

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 simple three-optional-param read tool, the description covers scope, data source, cost, and access requirements. The remaining gap is that the return payload is only implied by a field list (APY/TVL/7d change) rather than stated, and there is no output schema to compensate.

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 sort, limit and min_tvl_usd are already fully documented in the input schema. The description adds nothing about parameter behavior (e.g., how min_tvl_usd interacts with cross-chain pools), so the baseline of 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?

The description names a specific resource (raydium-amm pools) and enumerates what comes back (APY, TVL, 7d APY change) on DefiLlama data. Combined with the protocol-specific name, an agent can tell this apart from buy_yields_chain_solana or buy_yields_token_* siblings without opening a schema.

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?

It gives access/payment logistics but never says when to pick this over the sibling yields tools (chain-level or token-level lookups) or when it is the wrong choice. The only implicit signal is 'across chains', which hints the tool is not chain-filtered, but nothing states exclusions.

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