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

Annotations already declare readOnlyHint and openWorldHint, and the description adds meaningful behavioral context by listing the on-chain calls (balanceOf, decimals, symbol) and the return format. It does not contradict annotations and provides useful detail beyond the structured fields.

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 concise sentences. It front-loads the primary purpose and then lists the return values and implementation calls, with no redundant or unnecessary words.

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 tool with two parameters and no output schema, the description is fairly complete: it states the network, the resource, the return values, and the contract calls. It lacks explicit error handling or edge-case details, but the annotations and simplicity reduce the burden.

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 the baseline is 3. The description adds slight context by explaining that the token address is used to call decimals and symbol, and that a wallet address is for checking balance, but this largely mirrors the schema without significant new insight.

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 gets an ERC-20 token balance for a wallet on Mezo testnet, using a specific verb and resource. It distinguishes from siblings by specifying the network in both the name and description, and details the return values, making the purpose unambiguous.

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 for when to use this tool (Mezo testnet ERC-20 token balance) and mentions the specific contract calls. However, it does not explicitly name alternatives for when not to use it, such as mainnet or other chains, so it stops short of full exclusion guidance.

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