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

The annotation readOnlyHint=true already covers the safety profile, so the description need not restate that. It adds the 'private' qualifier, which hints at authorization sensitivity, and clarifies the resource is split into trial and earned balances. However, it does not disclose any additional behavior such as response format, empty-balance handling, or access prerequisites.

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 a single, front-loaded sentence that states the action and the resource without any filler. Every word contributes meaning.

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 zero-parameter read-only tool, the description is nearly complete: an agent knows what will be read and roughly what the result represents. The only minor gap is the lack of any detail about the output format, but since no output schema exists, the meaning of 'balances' is still reasonably self-evident.

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 tool has zero parameters and schema coverage is 100%, so the baseline is 4. There is nothing for the description to add about parameters, and it correctly introduces no parameter-related confusion.

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 uses a specific verb ('Read') and clearly names the resource ('your private trial and earned balances'). It distinguishes the tool from other read-oriented siblings like read_ledger and read_reputation by identifying the exact wallet balance concept.

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 is given about when to use this tool versus alternatives, such as read_ledger for transaction history or read_reputation for reputation balances. The context is implicit at best and provides no exclusions or routing cues.

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