getHistoricalBalance

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

Annotations already mark this as readOnly and idempotent, so the safety profile is clear. The description adds context about historical scope and token types, but doesn't disclose limitations such as what happens if a block height/date is invalid or if the address has no holdings. This is acceptable given annotation coverage.

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 a single sentence that is reasonably concise. It front-loads the main purpose, though 'Commonly used to' adds little value and could be removed. Overall, it is efficient and not overly verbose.

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?

The description is incomplete due to the phantom block height/date parameter and lack of any output/return description. For a read-only tool with no output schema, the description should at least indicate what data is returned. The mismatch between description and schema further hampers completeness.

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 description references a 'block height or date' parameter, but the input schema only includes chainName, walletAddress, and authToken — with additionalProperties false. This is a critical mismatch that would mislead the agent into trying to pass an unsupported parameter. Schema coverage is only 67% and the description fails to clarify existing params, instead inventing a phantom one.

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 fetches historical balances (native, ERC20, ERC721, ERC1155) for an address at a specified block height or date. It uses a specific verb ('fetch') and resource ('tokens held by an address'), distinguishing it from sibling tools that focus on current balances or single token types.

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 usage for historical balance queries but does not explicitly compare with alternatives like getTokenBalance or getERC20Balance. It lacks clear 'when to use' or 'when not to use' guidance, though the historical/block context provides some implied direction.

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