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

With no annotations present, the description carries the full burden and does so well: it discloses that the call is paid ($0.002 USDC on Base or Solana), that no account or API key is needed, that failed calls are not charged, and that the underlying data is DefiLlama. It does not cover rate limits, latency, or response shape beyond the named fields.

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?

The opening word 'Paid' front-loads the most decision-relevant fact, followed by scope, payload, cost, and endpoint in a tight sequence with no filler. The dense, clause-heavy formatting is efficient though slightly telegraphic.

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 read tool with three optional parameters and no output schema, the description covers cost, payment rails, failure billing, data source, and the returned metrics, which compensates for the missing output schema. Only response structure and pagination behavior remain unaddressed.

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 schema. The description adds marginal meaning by naming APY, TVL, and 7d APY change as the surfaced metrics, hinting at the sort options, but it supplies no syntax or default details beyond the schema.

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 the specific resource (live DeFi yield pools for the alchemix-v3 protocol, across chains) and the fields returned (APY, TVL, 7d APY change), so an agent knows exactly what it retrieves. It does not explicitly contrast itself with the chain-level or token-level yield siblings, relying on the protocol name in the tool name for differentiation.

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: call this when you want yield data for the alchemix-v3 protocol specifically. There is no explicit when-not guidance or pointer to the alternative tools (buy_yields_chain_* or buy_yields_token_*) for broader or token-focused queries, so the agent must infer routing from the name alone.

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