Get native balance

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is well covered. The description adds value beyond annotations by detailing that the tool works across specific networks and L1 keys, and that it returns both wei and formatted values. This complements the annotations without contradicting them.

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 two sentences, front-loaded with the primary action and scope. It efficiently covers network options and return information without fluff. Every sentence earns its place, and there is no unnecessary repetition or verbiage.

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, an output schema exists to define the return structure, and the description complements it with concrete network details and return format. It covers all required information for an agent to select and invoke the tool correctly: what it does, which networks it operates on, and what it returns. Nothing essential 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 coverage is 100%—both parameters have descriptive text in the schema. The description repeats the network list and return format but adds no new meaning beyond what the schema provides. Since the schema already documents the parameters thoroughly, a baseline 3 is appropriate; the description does not elevate understanding further.

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 a specific verb and resource: "Get the native token balance" of an address on an Avalanche EVM chain. It distinguishes from sibling balance tools (e.g., avax_pchain_get_balance, avax_xchain_get_balance) by scoping to EVM chain native tokens. The network options are explicitly enumerated, leaving no ambiguity about what this tool does.

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 provides clear context on when to use the tool: for querying native AVAX balance on C-Chain or Fuji, or native token on a listed L1. It does not explicitly name alternative tools for P/X-chain balances, but the scope is implied to be EVM-only, which sufficiently guides selection. A minor gap is the lack of an explicit 'for other chain balances use X' statement.

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