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 the paid model ($0.005 USDC on Base or Solana), that no account or API key is needed, that failed calls are not charged, the upstream data source (DefiLlama), and the endpoint URL. It stops short of describing response shape or whether empty protocol results are billed differently.

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?

Leading with "Paid." front-loads the single most decision-relevant fact, then scope, then cost/access terms, then URL. Every sentence carries information an agent needs before invoking a paid endpoint; 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 zero-required-parameter read tool with a fully documented schema and no output schema, the description supplies the missing pieces an agent needs: what data comes back, what it costs, how payment works, and where it goes. Only the response envelope and billing edge cases are left unstated, which is a minor gap.

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 documented in the schema with defaults and ranges. The description adds no extra meaning about parameter behavior (e.g., how min_tvl_usd interacts with cross-chain aggregation), 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?

"Live DeFi yields for origin-ether: its pools across chains with APY, TVL, 7d APY change" names a specific resource, scope (protocol-level, all chains), and the concrete fields returned. An agent can distinguish it from buy_yields_chain_* or buy_yields_token_* by the protocol scoping, though the description never states that distinction explicitly.

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 context is implied by the scope (per-protocol pool yields) and the payment/logistics details make it safe to attempt, but there is no explicit when-to-use or when-not-to-use guidance and no pointer to the sibling chain- or token-level yield tools that overlap with it.

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