Native + ERC-20 wallet balance

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds valuable behavioral context: that the call costs $0.002, supports five specific chains with a default, and optionally checks an ERC-20 token. These details go beyond annotations, though the return format (e.g., wei vs ether) is not disclosed.

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 plus a cost note, front-loaded with the core purpose. Every word earns its place; there is no redundancy or fluff.

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 the tool's simplicity (3 parameters, no output schema), the description covers the input purpose and constraints. However, without an output schema, the description should ideally hint at the return format (e.g., numeric value in wei) to fully inform the agent. This omission leaves a gap in 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?

Schema coverage is 100% with clear descriptions for all three parameters. The description confirms the purpose of the parameters (native balance + optional ERC-20) but adds no new meaning beyond the schema. The cost note is not parameter-specific. Baseline 3 is appropriate.

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 verb ('get balance'), resource ('wallet address'), and scope ('native token plus optional ERC-20 token across 5 chains'). This definitively distinguishes it from sibling tools like get_crypto_price or get_crypto_market_data, which serve different purposes.

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 (if you need a wallet balance, use this tool), but it does not explicitly state when to use it over alternatives, nor does it mention when not to use it. No alternative tools are named or excluded, leaving usage guidance implicit.

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