spl-token_getBalance

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

No annotations are provided, so the description carries the full burden. It successfully communicates that the tool is a read-only operation returning a balance, with the dual behavior based on the mint parameter. It lacks details on error cases or return format, but for a simple query, it is adequate.

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 concise at two sentences and 20 words. The first sentence immediately states the purpose, and the second adds a critical condition. No unnecessary words or repetition.

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?

Given the low complexity of a balance-checking tool with only two parameters and no output schema, the description provides sufficient context. It explains the core functionality, the parameter behavior, and covers the primary use cases.

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% coverage, but the description adds semantic value by explaining the special behavior of the mint parameter (omitting it returns SOL balance). This goes beyond the schema's mere type description.

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's function: 'Get token or SOL balance for a wallet.' The condition 'If mint is omitted, returns native SOL balance' further clarifies the behavior. It distinguishes itself from sibling tools like sol_get_balance by explicitly covering both token and SOL balances.

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 a clear condition for when to omit the mint parameter to get SOL balance. However, it does not explicitly mention alternatives like sol_get_balance or provide guidance on when not to use this tool.

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