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

Annotations already mark the operation read-only, idempotent, open-world, and non-destructive. The description adds non-obvious behavior by disclosing that tokens without a USD price are omitted from results, which could surprise callers expecting a complete balance report. This is genuine added transparency beyond the structured 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?

Two sentences with no filler; the core operation is first, followed by the essential output/filter detail. Every clause earns its place and the text is appropriately sized for the tool's complexity.

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 simple read-only paginated list tool, the description covers the required semantics (address-based ERC-20 balances), output shape (human-readable quantities and USD values), and noteworthy filtering behavior. The schema covers all parameter details and annotations cover safety, so no critical invocation-relevant information is missing.

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 address, chainid, page, and offset are already documented. The description does not add parameter-level detail beyond mentioning that balances are tied to 'an address' and that USD filtering occurs; it neither compensates for gaps nor overrepeats schema content.

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?

Clearly identifies the operation ('Get'), resource ('ERC-20 tokens held by an address'), and output characteristics ('human-readable quantities and USD values'). It also states an important selection behavior (filtering tokens without USD prices), which distinguishes it from sibling balance/list tools like get_native_balance and get_token_transfers.

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 should be used when an agent needs an address's ERC-20 holdings with USD valuations, but it never explicitly states when to prefer it over siblings or when not to use it (e.g., native balance via get_native_balance, token metadata via get_token_info). No alternatives or exclusions are given.

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