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

No annotations provided, so description must carry full burden. It states 'Scans balances' but does not disclose behavior like network latency, rate limits, or whether it returns all tokens or only a subset. For a read-only operation, more detail on what the tool does (e.g., 'returns current balances') would improve transparency.

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?

Single sentence of 16 words, front-loaded with verb. No wasted words. Efficiently conveys core functionality.

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 2 parameters and no output schema, description is minimally complete. It covers purpose and parameters but lacks information about return format (e.g., list of token objects) or potential limitations. Context signals are minimal, so more detail would improve completeness.

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. Description adds context that tool retrieves 'native balance and ERC-20 token balances', which clarifies the purpose of parameters but does not add extra syntax or constraints beyond schema.

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?

Description clearly states the verb 'scans' and resource 'native balance and ERC-20 token balances', with scope 'for a wallet address on Base or Ethereum'. This distinguishes it from sibling tools which are all unrelated (e.g., airport, DNS).

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?

No explicit when-to-use or when-not-to-use guidance. The description implies use for checking balances, but does not mention alternatives or exclusions. Siblings include other blockchain-related tools like getContractAbi, so a comparison would help.

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