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

With no annotations provided, the description carries the full burden, and it clearly signals a read-only operation through the verb 'check' and the noun 'balance', implying no side effects. It also specifies that the balance belongs to the authenticated user, hinting at authentication requirements. While it lacks details like rate limits or error behavior, the simplicity of the operation means the description is sufficiently transparent.

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, compact sentence that front-loads the action ('Check') and the resource ('RYLA credit balance'), followed by the user scope. It contains no filler or redundant information, making it highly concise and well-structured.

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 tool has no parameters, no annotations, and no output schema, the description adequately covers the essential context: what action is performed, on whose account, and what resource is queried. It does not specify the response format or units, but 'current credit balance' reasonably implies a numeric value, and the tool's low complexity makes this a minor gap.

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 zero parameters, so there are no parameter semantics to describe. The baseline for zero-parameter tools is 4, and the description appropriately focuses on the action and return value rather than parameters.

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 ('check') with a clear resource ('RYLA credit balance') and scope ('authenticated user'), making the tool's function immediately obvious. It is clearly distinct from the sibling tools, which are all about generation, gallery, or server info, so there is no ambiguity about what this tool does.

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 implies usage in the context of checking an authenticated user's balance before or after generation tasks, but it does not explicitly state when to use this tool over alternatives or when not to use it. No sibling tool handles balance checks, so context is inferred rather than explicitly articulated.

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