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

The description adds substantial behavioral context beyond the readOnly/openWorld/idempotent annotations: it discloses the data pipeline (CDP Data API with Alchemy fallback, DexScreener for USD), pricing ($0.02 per call), the prepaid x-credit-token header requirement, and the free daily call. This is exactly the kind of rate-limit and auth context agents need.

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 key purpose is front-loaded in the first clause, followed by scope, data sources, authentication, and pricing. It is fairly dense but every sentence carries useful information; the pricing and header details could arguably be moved elsewhere but are still relevant to using the tool correctly.

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 that an output schema exists, the description does not need to explain return values. It covers the network (Base), scope (all non-zero ERC-20 tokens), data sources, fallback behavior, authentication, pricing, and free-tier limits—everything an agent needs to invoke the tool correctly.

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?

The input schema has 100% coverage for the single `address` parameter, so the baseline is 3. The description repeats that address is required and confirms it is a Base address, but adds no format details such as 0x-prefixing, checksum requirements, or ENS support.

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: all ERC-20 holdings for a Base wallet, including every non-zero token, metadata, live USD value, and a total. This clearly distinguishes it from sibling tools like wallet_tokens or wallet_summary by emphasizing completeness and USD valuation.

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 clear context for when to use the tool: when a complete ERC-20 portfolio for a Base address with USD values is needed. It also states required input and that no wallet/API key is required, but it does not explicitly name alternatives or exclusion conditions relative to sibling tools.

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