wallet_balances

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

With no annotations provided, the description carries full burden. It discloses pricing ($0.002/call), requirement of a wallet address, data source (Coinbase indexed data API), supported networks, and that symbols/decimals are populated for whitelisted tokens (USDC always included). Rate limits and failure modes are not mentioned, but for a read-only tool this is sufficient.

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 two sentences plus a brief network list and note on whitelisted tokens. It is front-loaded with the most critical info (cost, requirement, capability). Every sentence adds value, with no redundancy or fluff.

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 that all token balances are returned and mentions that symbols/decimals are populated for whitelisted tokens. This gives a solid idea of the output structure. It could mention whether there is a limit on the number of tokens or pagination, but overall it is complete enough for an AI agent.

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 coverage is 100% with both parameters described. The description adds meaning beyond the schema: it explains that 'address' should be EVM 0x… or Solana base58 matching network, and for 'network' it lists all options and notes base as default. This provides context the schema alone does not.

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 retrieves all token balances for any address in one call, covering ERC-20 + native on EVM and SPL on Solana. It distinguishes itself from per-token contract calls and other tools like 'wallet_balance' (singular). The verb 'get' is implicit, and the resource is explicitly 'all token balances'.

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 explicitly states when to use this tool: when you need all token balances in one call, avoiding per-token contract calls and RPC wrangling. It lists supported networks. However, it does not explicitly mention when not to use it or name alternatives, such as 'wallet_balance' for single token queries.

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