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

The annotations already declare readOnlyHint=true and openWorldHint=true. The description adds meaningful behavior beyond that: the RPC/growthepie data sources, the billing exception when the chain RPC fails, and a prompt-injection caution about names and symbols being data rather than instructions. It does not cover latency, rate limits, or caching behavior.

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 definition is front-loaded with the returned metrics and uses two short safeguard sentences for billing and injection warnings. The first sentence is quite dense and comma-heavy, but no sentence 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?

An output schema exists, so the description need not explain return values. For a multi-chain RPC/growthepie metrics tool, the description covers sources, supported chains, asymmetric data availability, billing behavior, and a security note, leaving no critical gap for an agent to invoke it 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?

There is one required parameter, and the schema has 100% description coverage with a full enum for chain. The description repeats the chain names but adds no syntax, default, or semantic detail beyond what the schema already provides, so the baseline score of 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?

The description names the exact metrics returned (block time, TPS, base fee, utilization, transfer/swap USD cost, daily transactions, active addresses), the supported chains, and the data sources. This is a specific data-retrieval purpose that an agent can distinguish from the sibling catalog, funding, OI, perp, sample, and wallet-swap tools.

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 makes the data coverage clear, including that daily transactions and active addresses are only available for Base and Arbitrum. However, it does not explicitly say when to use this tool versus alternatives, nor does it provide exclusions or prerequisites beyond the chain enum.

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