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

Annotations only declare readOnlyHint and openWorldHint, so the description adds real value: it discloses return contents (percent of supply, holder labels, top-1/5/10 concentration with low/medium/high grading) and, importantly, the $0.004 USDC x402 payment requirement. It does not mention pagination or rate limits, but the cost and output profile go well beyond the 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?

Two sentences, front-loaded with what the tool returns and followed by the cost, with no filler. The middle clause listing holder labels is dense but informative rather than redundant.

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 carries the burden of describing return values and does so (supply percentages, holder type labels, concentration tiers, risk level). Combined with the read-only annotation and the cost disclosure, an agent has what it needs to invoke it; only usage routing against siblings is thin.

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 coverage is 100%, so the schema already documents address, chain, and limit with defaults. The description echoes the chain options but adds no new syntax or semantics for the parameters, matching the baseline-3 case where the schema does the heavy lifting.

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+resource ("Top holders of any token") plus the supported chains, which is unambiguous and clearly distinct from sibling token tools like token_chart or token_price. It does not explicitly contrast itself with adjacent siblings such as token_scan or token_report, which is the only thing keeping it from a 5.

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 context is implied by "the strongest single rug-pull signal," which suggests the tool is for concentration/rug-risk assessment, but the description never states when to prefer this over token_scan, token_report, or token_verdict. No explicit when/when-not guidance.

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