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, the exact price ($0.002 USDC), accepted payment chains (Base or Solana), that no account or API key is required, and that failed calls are not charged. The data provenance (DefiLlama) is also stated. It does not mention rate limits, caching/freshness guarantees, or what a failure response looks like, which keeps it below a 5.

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 text is a single dense, front-loaded block with zero filler: purpose first, then returned fields, then price, access conditions, billing behavior, and the endpoint URL. Every clause carries information. Slight deduction for the run-on delivery that mixes purpose and commerce terms without separators, which makes skimming harder than it needs to be.

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 three-optional-parameter, read-only paid data endpoint with no output schema, the description covers everything an agent needs before calling: what is returned (APY, TVL, 7d change), the source, the cost, the payment rails, and the no-charge-on-failure guarantee. Parameter behavior is fully documented in the schema, so no gap remains that would block a correct call.

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 inline including defaults and ranges, so the schema already does the heavy lifting. The description adds no meaning beyond the schema for these parameters (no note on how sorting interacts with the TVL filter or what units the returned figures use). Baseline 3 is appropriate.

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 and scope: live DeFi yield pools for one protocol (helius-staked-sol) aggregated across chains, returning APY, TVL and 7d APY change from DefiLlama. That is clearly more than a restatement of the name. It stops short of a 5 because it never explicitly contrasts itself with the large family of sibling yield tools (chain-scoped, token-scoped, top-yields), leaving the agent to infer that 'its pools across chains' means protocol-scoped aggregation.

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: an agent can infer this is the tool for looking up yields for this particular protocol rather than a chain or token. There is no explicit when-to-use statement and no named alternative such as the chain-scoped or token-scoped yield tools for the same underlying asset. Purchase prerequisites are covered, but selection guidance against siblings is not.

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