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

Beyond the readOnly and non-destructive annotations, the description discloses mainnet sourcing, lamports/SOL output, conditional SPL token accounts, null tokens with a note when unavailable, invalid-address 400 behavior, and pricing. It also clarifies that failed calls are free while successful calls are charged, which is important operational context.

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 dense and front-loads the core purpose before output behavior, validation, and pricing. It is appropriately sized for a paid, single-parameter API, though the charging/repeat-call point is mentioned twice in slightly different 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?

With no output schema and only one parameter, the description supplies what an agent needs: what is read, what is returned, the fallback when token accounts are unavailable, invalid-address handling, and cost behavior. No important calling detail is left unspecified.

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 schema already fully documents the single 'address' parameter as a base58 Solana wallet address. The description adds a concrete example and a validation constraint: addresses that are not 32-byte base58 return 400 and are uncharged.

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 precise resource and scope: the SOL balance of a Solana wallet, read live from mainnet in lamports and SOL, plus SPL token accounts when available. It is clearly distinguishable from sibling chain-balance tools and from solana_token/solana_tx by its wallet-balance focus.

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?

It gives a concrete usage context: 'Use to check a Solana wallet before a payment.' It also notes that the tool is read-only and that each call is charged, but it does not explicitly name when to use a sibling alternative instead.

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