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

Annotations already disclose read-only, idempotent, and non-destructive behavior, so the description does not need to repeat safety. It adds some context by specifying 'normalized' usage and the list of categories, but does not address pagination, rate limits, or required authentication. With annotations covering the safety profile, a 3 is appropriate.

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, concise sentence with no filler content. It is front-loaded with the verb and resource, making it easily scannable.

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?

With 8 parameters and no output schema, the description is under-specified. It does not explain parameter semantics, return format, or any prerequisites like authentication. The high-level purpose is clear, but the tool's configuration and output are not sufficiently described for the agent to invoke it effectively.

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?

Schema description coverage is 0%, and the description only indirectly hints at the 'kind' parameter by listing usage categories. It provides no meaning for limit, time filters (start_time, end_time, days_back), group_by, account, or bucket_width, leaving the agent without sufficient context to set these parameters correctly.

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 action ('Get') and the resource ('normalized OpenAI organization usage'), and enumerates the specific usage categories (completions, embeddings, etc.). This distinguishes it from sibling tools like openai_billing_cost, which focuses on cost, and openai_billing_list_accounts.

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 for retrieving usage data but provides no explicit guidance on when to choose this tool over alternatives such as openai_billing_cost. There is no 'use this when' or 'instead of' statement, leaving the agent to infer from the name and resource.

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