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

Annotations are empty, so the description carries the full load — and it does disclose non-obvious behavior: Nansen aggregates across chains so no chain argument should be passed, and access is gated by x402 payment (0.02 USDC) or API key. It stops short of stating pagination or any edge cases, but the auth/payment and cross-chain aggregation context are exactly the kind of traits annotations would normally supply.

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 purpose and metric list, followed by usage triggers, then a bracketed access note kept in its own paragraph. Every sentence is functional; the payment block is slightly verbose but is necessary operational context rather than filler.

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?

There is no output schema, and the description compensates by naming the three returned values. With one required parameter, a stated chain-agnostic resolution rule, and explicit auth/payment instructions, an agent has everything needed to call this correctly.

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% with a single documented parameter, so the baseline is 3. The description exceeds that by adding a real constraint beyond the schema: 'pass the symbol only and do not pass a chain argument', explaining that symbols are resolved chain-agnostically — meaning an agent won't try to disambiguate with a chain field.

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 opens with a specific verb+resource — 'on-chain token holder distribution for a token' — and enumerates the exact metrics returned (holder count, top-10 concentration percentage, concentration score). It is distinguishable from siblings like get_smart_money_holdings or get_token_flows by its distribution-specific focus, though it never names a sibling directly.

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?

It gives concrete triggering questions: 'how many wallets hold a token', 'holder count', 'holder concentration', 'whale ownership', 'distribution risk'. That is strong positive routing guidance, but no when-not-to-use or explicit alternative is offered (e.g. when to prefer get_smart_money_holdings).

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