credits_balance

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds the valuable behavioral context that the call is free, which is not captured by annotations. It also clarifies the scope ('for this account'), adding practical meaning beyond the structured metadata.

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 with no unnecessary words. The main action and resource appear immediately, and the cost note is a minor parenthetical that adds value without bloating the text.

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, idempotent tool, the description is fully adequate. It states what the tool does, for which account, and that it is free. No output schema exists, but the expected result (the remaining balance) is clearly implied by the description.

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 the schema describes an empty properties object with 100% coverage. The description does not need to explain parameters because there are none. The baseline of 4 for no-parameter tools is 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 a specific verb ('Show') and a clear resource ('remaining dVeracity API credit balance for this account'), which makes the tool's purpose unambiguous. It is easily distinguished from its siblings, none of which relate to credit balance. The parenthetical '(free)' adds a useful note that the endpoint is free of charge.

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 makes the context clear: use this to check the available API credit balance for the current account. There are no direct sibling alternatives for this function, so explicit exclusions are unnecessary. However, it does not explicitly state when to use it versus other account-quota or billing tools, though none appear among the siblings.

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