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

With no annotations provided, the description carries the behavioral disclosure burden. It explicitly discloses that the call is free and does not consume a credit, implying a non-destructive read operation. This is sufficient for a simple, parameterless status tool, though it could mention failure modes like invalid API keys.

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?

Two concise sentences with no fluff. The core action is front-loaded, and the cost-related note is a valuable second sentence that earns its place.

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 parameterless, read-only status tool with no output schema, the description is complete: it names the return value (a number), identifies the auth context, and clarifies the cost behavior. Nothing essential is missing.

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, so the baseline is 4. The description adds the meaningful context that the operation is tied to the authenticated API key and returns a remaining count, which is all the parameter semantics needed.

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?

States a specific verb and resource: returns the number of extraction credits remaining on the authenticated API key. This clearly distinguishes it from sibling tools like parse_document or list_schemas.

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 gives clear context for when to call this tool: to check remaining credits on the authenticated key. It also notes the tool is free and does not consume a credit, which is relevant usage guidance. No exclusions are needed since no sibling overlaps with this function.

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