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

Beyond the annotations (readOnly/idempotent/openWorld/non-destructive), it discloses data freshness ('decays in hours'), the indexing source (CDP-indexed events), and the full payment/auth model: $0.04/call over x402 on Base, prepaid x-credit-token header for unlimited calls, no free tier, no API key. These are operationally critical and not derivable from annotations.

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 the core analytical question and answer, and the analytical content is dense rather than padded. It runs long, mixing billing/payment logistics into the same block as the analytical framing, so it is slightly heavier 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?

An output schema exists so return values needn't be explained, and the description covers the analytical semantics, the sibling it complements, freshness decay, and the payment/auth requirements. Nothing an agent needs to call it correctly is missing.

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 the schema fully documents both parameters and the baseline is 3. The description adds only 'Required input: address' and the implicit 24h/default window, which largely restates 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?

States a precise verb+resource: the largest Base-token transfers in the last 24h, classified by direction (whales INTO DEX pools = sell pressure vs pulling OUT = accumulation). It explicitly distinguishes itself from holder_forensics ('who could dump' vs 'is anyone dumping now'), so an agent can tell them apart without opening either schema.

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 complement framing against holder_forensics gives a clear when-to-use signal, and the 'is anyone dumping now' framing scopes the temporal window. It does not state explicit when-not conditions (e.g., for very low-liquidity tokens or other chains), so it stops short of a full 5.

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