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

Annotations already declare readOnlyHint=true (safe read), openWorldHint=true (external data), and destructiveHint=false (no side effects). The description adds significant beyond-annotation value: it explicitly discloses the BYOK Etherscan model ('your key, your quota'), the $0.01/call x402 pricing on Base, and the heuristic nature of the score. This is rich behavioral context that annotations alone don't cover.

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 a tight three sentences, each earning its place: the first explains the core function and scoring, the second explains the key BYOK model and caveats, the third summarizes pricing and payment method. No filler, perfectly front-loaded.

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 4 parameters, 100% schema coverage, readOnlyHint annotations, and no output schema, the description adequately explains the tool's function, constraints, and pricing. It's complete for a wallet profiling tool. Minor omission: doesn't specify if multiple wallets yield individual scores or an aggregate, but the schema's array type suggests individual. Still highly functional.

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 description coverage is 100%, so the baseline is 3. The description adds value by explaining the BYOK trade-off: 'Leave empty to use a free keyless Blockscout explorer' vs providing your own key for higher rate limits. It also clarifies concurrency is 'kept low to respect your Etherscan rate limit'. This contextualizes the parameter purpose beyond the schema's technical definitions.

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 clearly states the tool profiles a wallet on-chain using specific metrics (age, tx activity, contract & token diversity) and outputs a 0-100 airdrop-farming readiness score. This distinguishes it from sibling tools like 'rug-pull-scorer' or 'whale-wallet-tracker' which have different purposes.

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 includes a clear caveat 'Not a guarantee of eligibility for any specific airdrop -- a heuristic signal only' which sets expectations appropriately. However, it doesn't explicitly state when NOT to use this tool vs alternatives like 'rug-pull-scorer'. The BYOK model and pricing are mentioned but not compared to sibling tools.

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