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

Annotations already cover read-only, idempotent, non-destructive, open-world behavior, so the description's remaining job is return semantics, which it does well (ranked by USD value, holder counts, 24h balance change). It omits credit cost per call and result freshness/caching, which matter for a paid open-world data API.

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 question and answer in one sentence, then a compact example. The example largely duplicates the schema's examples array, so that sentence is close to redundant, but nothing else is wasted.

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 return-value burden and does so: it names the ranking metric and the fields (holder counts, 24h change). Missing only pricing/freshness context, which is partly covered by the schema's _apiKey note.

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% and each parameter is documented with defaults and ranges, so baseline 3 applies. The description's inline example merely restates the schema's own examples without adding format or constraint detail beyond them.

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: returns tokens currently held by Nansen Smart Money wallets on a chain, ranked by USD value. This clearly separates it from nansen_smart_money_netflow in concept (holdings snapshot vs. flows), though it never names that sibling explicitly.

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 usage context is implied — you'd call this to see a snapshot of what smart wallets hold — but there is no explicit when-to-use, when-not-to-use, or reference to the netflow sibling as the alternative for flow analysis. The agent must infer the choice from the name pair.

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