Score a TOEFL Writing response

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

Beyond the annotations, the description discloses that the call is a metered AI scorer drawing on the daily spend ceiling and that it refuses with a machine-readable code rather than silently falling back to a cheaper engine. It also includes the ETS non-affiliation disclaimer, all of which is useful behavioral context not present in the annotations.

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 front-loaded with purpose and usage, then adds behavioral and legal context. It is slightly longer than necessary due to repeated ETS disclaimer phrasing, but every major section 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?

Given no output schema, the description still covers the return value, the metering behavior, the spend limit refusal, the parameter selection rule, and where to find response shapes and error codes. For a tool of this complexity, it is complete enough for an agent to invoke it correctly.

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 coverage is 100%, so the schema already documents each parameter. The description adds meaningful selection semantics by explaining the either/or relationship between item_id and task_type plus prompt, and clarifies that prompt is only for inline coursework. This goes beyond the schema baseline.

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 states a specific verb and resource: score a learner's written response to a TOEFL iBT Writing task and return an automated practice score with a rationale. This clearly differentiates it from the sibling prompt-list and prompt-retrieval tools.

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?

It explicitly tells the agent how to choose between item_id and task_type plus inline prompt, and references the prompt tools as the source of item_id. This gives a clear selection rule without leaving the agent to infer the param relationship.

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