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

Annotations already mark this readOnly, openWorld, and non-destructive, so the description only needs to add extra behavioral context. It meaningfully adds the x402 cost ($0.005 USDC) and the 10-token cap, which are not available from annotations.

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 short sentences with no filler: it front-loads the operation and outputs, then states a key constraint/cost. It does not restate schema details or annotations.

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 two documented parameters and no nested objects, the description is nearly complete: it covers the input intent, result scope, token cap, and cost. It could note the exact return shape or whether the snapshot is always at the latest block, but those are minor omissions for a lightweight read tool.

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 descriptions already cover 100% of the parameters with address/token patterns and constraints, so the baseline is 3. The description reinforces that native ETH is always included and the token list is optional, but adds no new syntax or format detail beyond the 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?

States a concrete operation—take a Base wallet snapshot—and explicitly scopes it to native ETH plus up to 10 ERC-20 balances. This differentiates it from sibling single-focus tools like base_wallet_balance and base_erc20_balance by describing a combined, batched read.

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 phrase 'in one call' implies a batching use case, but the description never names alternatives or says when not to use it. There is no explicit routing guidance versus the sibling balance tools, though the benefit of a combined call is clear.

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