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

The description leads with the $0.002 USDC per-call cost, which the readOnlyHint annotation does not convey, and notes the alternate x402 payment path is handled via api_key. It stops short of stating rate limits, max response size, or pagination semantics beyond limit/offset.

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?

Cost is front-loaded in the first clause and the rest is a compact enumeration with no filler. The dataset glosses are slightly dense but each adds real semantic value, though the sentence runs long and mixes pricing, dataset taxonomy, and parameters in one breath.

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?

With six parameters and no output schema, the description covers dataset selection, filtering, pagination and serialization adequately. It does not describe the shape of returned rows, which would matter more given the absence of 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?

With only 17% schema coverage, the description carries the load well: it explains q as a keyword filter, limit as 1-1000, offset, and format as json/csv, plus the meaning of each dataset enum value. The only unaddressed parameter is api_key, which the schema itself documents in detail.

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?

States a specific verb and resource ('Rows from one dataset listing') and enumerates the five valid datasets with brief characterizations (e.g. '~155 Chainlink on-chain prices'). It is clearly a row-fetch tool, though it never explicitly contrasts itself with siblings like list_datasets, preview_dataset, or free_datasets.

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?

The paid-per-call framing and the dataset menu imply when the tool applies, but there is no explicit 'use this instead of X' routing against preview_dataset, list_datasets, or buy_dataset. An agent must infer that preview is for sampling and this is for full listing.

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