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

Annotations already declare readOnlyHint=false and idempotentHint=false, and the description adds the concrete consequence that each question can be graded only once. It also summarizes the response, including returning the final score after the last question, though it does not describe the error behavior for a duplicate grading attempt.

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 tight sentences with the core action, workflow context, return summary, and one-time constraint front-loaded. There is no filler and every sentence contributes useful invocation context.

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 an output schema, annotations, and 100% schema coverage, the description supplies the needed workflow context: it follows start_quiz, grades one answer, can be used only once per question, and returns final score after the last question. No critical invocation context 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?

Schema description coverage is 100%, so the schema already documents quiz_id, question_id, answer format by question type, and the language enum. The description only implies the start_quiz workflow and adds no parameter-level syntax beyond the schema, which fits the baseline of 3.

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, 'Grades', and a specific object, 'one answer from a start_quiz round'. It clearly distinguishes itself from start_quiz by being the downstream grading step rather than the quiz-creation step, and the return details further pin the purpose.

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?

Establishes the prerequisite context that it operates on a start_quiz round and enforces the key constraint that each question can be graded once. It does not explicitly say when not to use it or name a direct alternative beyond start_quiz, so it falls short of a 5.

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