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

Annotations already establish read-only, non-destructive, open-world behavior, so the bar is low, yet the description adds genuinely new operational context: 0.005 USDC per call, 3000 ms p95 response time, and airdrop-spam filtering. It also discloses what the payload contains (native plus major-token balances and latest transfers in/out) in a single call.

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?

Front-loaded with the use case and exclusions, and nearly every clause carries load. Minor waste remains: the chain list 'Ethereum, Base or Solana' is repeated twice in adjacent sentences, and the trailing 'Category: Data.' adds nothing operational.

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?

An output schema exists, so return-shape explanation is not required, and the description still characterizes the payload plus spam filtering. Cost, latency, supported chains, exclusions and the address-family constraint are all covered, leaving nothing critical an agent needs before invoking it.

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 address formats, chain enumeration and historyLimit bounds; that sets the baseline at 3. The description confirms the supported chains and that history returns transfers in and out, but adds no syntax, defaults, or edge-case guidance beyond what the schema already carries.

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 states a specific resource and scope: multi-chain wallet balances, portfolio, and recent transaction history for an address, restricted to Ethereum, Base and Solana. An agent can tell exactly what data comes back. It does not, however, differentiate itself from the sibling blackwood_wallet_balances, which an agent could plausibly confuse with the 'wallet balance' framing used here.

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?

It gives an explicit use trigger ('when you need a multi-chain wallet balance... or recent transaction history') and a thorough when-not list: uSD values, NFTs, DeFi positions, long-tail tokens, and chains beyond the three supported. The exclusions are the harder half of routing and they are spelled out rather than implied.

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