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

With no annotations, the description carries the full behavioral burden. It does disclose a genuinely useful trait beyond the schema: the $0.002 USDC pay-per-call cost model. However, it omits rate limits, error/empty-address behavior, and the shape of the response for a read tool with no output schema.

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?

Two tight sentences with the core payload (what balances are returned) front-loaded and the cost caveat last. Slightly marred by the bracketed '[Solana by default]' prefix, which is cryptic without the sibling context.

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 one-parameter read tool with no output schema, the description should explain the return shape more than 'native SOL plus every SPL token balance'. It covers the essentials and pricing but leaves chain-variant behavior (the 'by default' claim) and failure modes unexplained.

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?

There is only one parameter and schema coverage is 100% ('Solana wallet address'), so the schema already documents it fully. The description adds no format, chain-variant, or address-validation detail, making the baseline 3 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 states concretely what the tool returns: native SOL balance plus all SPL token balances (including USDC) for a Solana address. That is a specific resource and scope, sufficient to distinguish it from siblings like tx or trending. It falls short of a 5 because the bare name 'account' is ambiguous and the '[Solana by default]' bracket muddies the relationship with the explicitly named sibling solana_account.

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?

No guidance on when to pick this tool over solana_account, snapshot, or token — despite an overlapping sibling set. The only conditional information is a pricing note ('Pay-per-call'), which is cost data, not usage direction.

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