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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool gets the 'current credit balance' and is 'Free', which hints at read-only and cost-free behavior, but does not elaborate on side effects, rate limits, or output details.

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 very short (two phrases) and gets to the point. It is front-loaded with the main action. However, it could be structured into a full sentence, and the 'Free.' part feels slightly detached.

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 no parameters, no output schema, and no annotations, the description is fairly complete for a simple retrieval. It tells the agent what the tool does ('get current credit balance') and that it is 'Free'. No missing critical information for basic use.

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 coverage is 100% (since there are no parameters to describe). Per the rubric, 0 parameters yields a baseline of 4. The description does not need to add parameter semantics.

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 verb-resource pair 'Get current credit balance', which accurately describes the tool's function. It distinguishes itself from sibling tools like 'check_domain_availability' and 'search_names' by focusing on a unique resource (credit balance).

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 includes 'Free.' which implies simple, unrestricted usage, but does not explicitly state when to use this tool versus alternatives or provide exclusions. The context is clear enough for a simple retrieval tool.

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