wallet_balance

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes the return format ('list of token balances (symbol, amount)') and includes critical operational context ('Price: $0.002 USDC per call'), which are valuable beyond basic functionality. However, it doesn't mention rate limits, error conditions, or authentication requirements.

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 efficiently structured with clear sections (purpose, usage, returns, price) in just four sentences. Each sentence adds distinct value without redundancy, making it easy to parse and front-loaded with essential information.

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 tool with 2 parameters, 100% schema coverage, and no output schema, the description provides strong context: purpose, usage guidelines, return format, and pricing. It adequately compensates for the lack of annotations and output schema, though it could benefit from mentioning error handling or data freshness.

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 100% description coverage, providing a solid baseline. The description adds meaningful context by clarifying what constitutes valid addresses ('Ethereum 0x... or Stellar G...'), which complements the schema's enum for 'chain' and description for 'address'. This enhances understanding beyond the structured fields.

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 specific action ('Get the token balances') and resource ('any Ethereum or Stellar wallet address'), distinguishing it from siblings like token_price or whale_activity. It precisely defines the tool's function without ambiguity.

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 includes an explicit 'Use when' section that specifies the exact scenario for using this tool ('You need to look up the token holdings of an Ethereum or Stellar wallet address'). This provides clear guidance on when to select this tool over alternatives like token_price or defi_tvl.

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