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

Annotations already declare readOnlyHint=true, and the description adds contextual value by noting a cost of 0.01 USDC and the disclaimer 'Not financial advice'. This goes beyond the safety profile provided by annotations, alerting the agent to a financial cost and a caveat. No contradiction with annotations.

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 extremely brief and front-loaded with the core purpose. Every fragment ('Native balance + nonce', 'BSC/Base', '0.01 USDC', 'Not financial advice') adds distinct information without redundancy. It is a model of conciseness, though it sacrifices completeness for brevity.

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?

With no output schema, the description should clarify what the agent will receive (e.g., balance value, nonce, network). It does not. It also leaves the '0.01 USDC' ambiguous (is it a fee, a minimum, a cap?) and lacks any mention of error cases or rate limits. For a read-only tool with only two parameters, a bit more detail would make it complete, but current gaps leave the agent uninformed about return format and pricing semantics.

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 0%, so the description should compensate by explaining parameters. It only implies the 'network' parameter via 'BSC/Base' but does not mention the 'address' parameter or its requirement, nor the 'both' option for network. The description adds minimal semantic value over the raw schema, leaving the agent to guess how to populate parameters correctly.

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 states a specific resource ('Native balance + nonce') and scope ('BSC/Base'), which distinguishes it from sibling tools like 'gas' or 'wallet'. It does not use an explicit verb like 'get' or 'fetch', but the intent is clear enough. The network scope adds differentiation, so slightly above average.

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 gives clear context that the tool works on BSC and Base networks, which hints at when to use it (for native balance on those chains). However, it does not explicitly mention when not to use it or point to alternatives. There is no comparison to siblings, so usage guidance is implied rather than explicit.

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