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

With no annotations, the description carries the behavioral burden. It explains what checking the balance relates to—credits that settle orders instantly—and confirms the tool performs a check rather than a purchase or mutation. It could explicitly state the response format, but the read-only nature is strongly implied.

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?

Three short sentences, each earning its place: the purpose, the credit behavior/context, and the top-up alternative. No redundant or filler content.

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 simple one-parameter balance check with no output schema, the description covers what the tool does, why it matters, and what related action to take. The main missing detail is the exact response format or currency of the returned balance, but this is 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 schema provides only a string field named apiKey with no description, and schema coverage is 0%. The description compensates by identifying it as your INKFLOW API key, giving the parameter concrete meaning beyond the bare schema.

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 and resource: 'Check the credit balance on your INKFLOW API key.' This clearly identifies the tool as a balance inquiry and distinguishes it from siblings like inkflow_quote, inkflow_order, and inkflow_topup.

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: credits allow instant purchases without a human, and it explicitly directs the user to inkflow_topup for topping up. It does not spell out explicit when-not-to-use conditions, but the intended use case is obvious.

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