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

Annotations already declare readOnlyHint and openWorldHint, yet the description adds real value: data is read straight from chain, burns are excluded from concentration, a wallets-only share is reported, exactness depends on whether full transfer history fits, and invalid input is not charged. It does not cover failure modes for non-token addresses or how coverage is reported in detail, 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 core identity (largest holders, ranked, on-chain) is front-loaded, and every sentence carries useful meaning about returns, accuracy, or billing. It is dense but not padded; minor cost is that the exactness caveat is buried mid-paragraph.

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 no output schema, the description does the work of naming the return fields (balance, percent, type, concentration metrics, level) and the accuracy caveat. It stops short of describing error behavior for invalid tokens or how partial coverage is surfaced, which would complete it for an open-world paid tool.

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 both the token address format and the 1-50 limit range are already documented in the schema. The description adds the ranking context but no syntax or format meaning beyond the structured fields, so baseline 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?

States a specific verb and resource: the largest holders of an ERC-20 token on Base, ranked, with per-holder fields and concentration metrics. That distinguishes it clearly from siblings like token_safety_check, chain_token and wallet_transfers.

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 description implies the use case (holder concentration analysis) and notes exactness conditions and x402 pricing, but never explicitly says when to use this over alternatives such as wallet_transfers or token_safety_check, nor names any exclusion.

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