check_balances

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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It states it reads balances (implying read-only), but doesn't disclose chain requirements (Base-specific), token standards supported, network behavior (RPC timeouts), or what happens with invalid addresses or non-ERC-20 token contracts. The Base chain constraint is mentioned but the behavioral implications aren't fully detailed.

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, efficient sentence that conveys the core purpose, chain scope, and optional token parameter concisely. It front-loads the primary function (get balances) and adds the optional token-checking behavior without redundancy. Minor room to add usage context, but the current text is tight.

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?

For a read-only balance-check tool with 100% schema coverage, the description is reasonably complete. It covers the main action, chain context, and token override behavior. However, with no output schema and no annotations, it could benefit from describing the return shape (e.g., a balance breakdown object) and handling of invalid tokens to be 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 the schema already documents both parameters. The description adds the detail that tokens are ERC-20 token addresses and that ETH is always included, which complements the schema. However, it doesn't explain wallet address format requirements beyond the schema's '0x...' hint, and doesn't clarify behavior when 'tokens' is omitted entirely.

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+resource ("Get ETH balance and ERC-20 token balances") and scopes it clearly to 'any wallet address on Base.' It distinguishes itself from siblings like check_allowance (which checks specific allowances) and get_token_info (which retrieves token metadata) by focusing on balance retrieval.

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 implies the tool is for checking wallet balances but doesn't explicitly state when to use it over alternatives like check_allowance or resolve_address. It mentions Base chain context which helps, but there's no explicit when-not-to-use or alternative guidance. The clarity of purpose partially compensates for missing explicit usage conditions.

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