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

With no annotations, the description carries the full burden and does substantial work: it discloses the paid model ($0.005 USDC on Base or Solana), that no account or API key is needed, and the failure policy ('Failed calls not charged'). That is exactly the kind of context annotations would normally supply; only the response shape and pagination behavior are left unspecified.

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?

Front-loaded with 'Paid.' so the cost signal is the first thing an agent reads, followed by what the data contains, then price/auth/failure terms, then the endpoint URL. Every sentence carries distinct information with no repetition.

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 paid GET endpoint with a fully documented schema and no output schema, the definition covers what the agent needs to decide and pay correctly. The only gap is that the returned payload shape is only sketched (APY, TVL, 7d change) rather than described, which is acceptable without an output schema.

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 schema does the heavy lifting. The description adds nothing about these parameters (e.g. that min_tvl_usd default of 100000 filters out small pools), so the 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?

The description states a specific resource and scope: live DeFi yield pools for the single protocol 'onre', across chains, with named fields (APY, TVL, 7d APY change) and the data source (DefiLlama). That implicitly separates it from the many buy_yields_chain_* and buy_yields_token_* siblings, but it never explicitly says so, leaving the differentiation to inference from the tool name.

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 only implied by the scoping phrase 'for onre'; there is no explicit statement of when to pick this over buy_yields_chain_base, buy_yields_token_usdc, or another buy_yields_protocol_* sibling. The pricing and payment details are useful decision inputs, but they are cost context, not routing guidance.

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