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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description need not repeat safety. It adds material behavioral context absent from annotations: free-call quota, paid x402/card billing, in-band payment parameter, GeckoTerminal data source, and a not-financial-advice caveat. It does not discuss errors, rate limits after payment, or freshness beyond the 24h metrics, keeping 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 description is dense but front-loads billing, then purpose, data source, and usage. The billing details consume substantial space, but they are behaviorally important. It is mostly efficient, with only mild redundancy between the title and the repeated 'token prices' phrasing.

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 the description need not explain return values, and it still mentions market cap, 24h volume, and 24h change. With annotations covering safety and the schema covering parameters and outputs, the definition is nearly complete. A 5 would require more on failure modes or payment failure behavior.

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 both parameters and the network enum. The description reinforces that one call covers up to 30 addresses on one network and lists per-token outputs, but adds no syntax or format detail beyond the schema. Baseline 3 is appropriate when the schema carries parameter semantics.

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 states a specific verb and resource: 'USD prices for up to 30 tokens on one network in one call.' The multi-token, single-network scope clearly distinguishes it from the single-token sibling token_price and from token_portfolio, so an agent can choose correctly without opening schemas.

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 an explicit usage context: 'Use token-prices to price a whole portfolio or watchlist in one call.' That is strong positive guidance, but it does not name the single-token sibling as the alternative when only one address is needed, so the when-not boundary is only implied.

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