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

Annotations already convey readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context: the call cost ($0.01/call), payment method (x402 on Base), and a warning about rate limits ('Keep this low on Etherscan's free tier to avoid rate-limit errors'). It does not contradict annotations. It could further disclose error handling or rate-limit behavior, but the added value is substantial.

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 single paragraph of four sentences with no redundant words. It front-loads the core purpose and then efficiently covers output format, prerequisites, and cost. Every sentence adds value, making it concise without losing clarity.

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?

Given no output schema, the description explains what the tool returns: current balance, flagged transfers, and recent token transfers, one row per wallet. It also mentions the payment model and intended usage context. However, it lacks details on the exact format of the output (e.g., whether balances are numerical or structured) and does not address edge cases like empty results or API errors. Slightly more detail would make it fully complete.

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 baseline is 3. The description adds meaning beyond the schema by explaining the purpose of 'minValueEth' ('Flag native transactions moving at least this much ETH') and giving usage guidance for 'maxConcurrency' ('Keep this low on Etherscan's free tier'). It also contextualizes the 'etherscanApiKey' parameter with 'bring your own key' vs keyless Blockscout. This elevates the score above baseline.

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 uses a specific verb ('Track') and clearly defines the resource ('large native ETH and ERC-20 token movements for any wallet(s)'). It distinguishes itself from siblings by listing what it does not require ('No RPC node, no wallet-connect, no browser') and mentions the API source (Etherscan multichain API). This makes the tool's purpose unambiguous and distinct among blockchain-related sibling 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 states when to use the tool ('Track large native ETH and ERC-20 token movements') and the output format ('one row per wallet'). It implies the user needs an Etherscan API key or can use a keyless explorer. However, it does not explicitly contrast with sibling tools like 'wallet-airdrop-profile' or 'insider-trading-tracker', nor does it state when not to use this tool. The context is clear but lacking explicit exclusions.

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