Ethereum: ethGetBalances

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

Annotations already declare the tool as read-only and idempotent. The description adds valuable behavioral context by warning about the precision difference between the two balance fields, which is critical for correct usage. This goes beyond what annotations provide.

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 short sentences with zero wasted words. The purpose is stated first, followed immediately by a critical usage warning. Highly efficient and front-loaded.

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 covers the essential point about output fields, but could explicitly state the return structure (e.g., object with 'balance' and 'humanReadableBalance'). However, given the simplicity of the tool and the strong annotations, it is largely sufficient.

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 zero parameters (100% coverage), so baseline is 4. The description does not need to add meaning to parameters but compensates by describing output field semantics, though this dimension specifically focuses on input parameters.

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 states it gets wallet balances on Ethereum. The explicit 'CRITICAL' note distinguishes the two output fields, which helps differentiate from sibling balance tools for other chains and clarifies the tool's specific output semantics.

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?

Provides explicit guidance on when to use 'balance' vs 'humanReadableBalance', which is a key usage detail. However, it does not mention when to prefer this tool over sibling balance tools (e.g., baseGetBalances), though the chain-specific name largely self-explains.

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